Energy storage system equalization control method and device

Abstract

The application discloses a kind of energy storage system equalization control method and device.The energy storage system equalization control method includes: the running state of equalization unit is judged in real time, when the running state of equalization unit is abnormal, standby instruction is sent to the equalization unit that appears abnormal;Determine whether the equalization unit that appears abnormal satisfies re-switching condition, if satisfy, re-switching instruction is sent to the equalization unit that appears abnormal.Through judging whether the equalization unit of system appears running state abnormality, and when abnormal, standby operation is carried out in time, abnormal equalization unit is avoided to other normal equalization unit in system interior for charge-discharge, avoid to produce internal circulation problem;And after standby operation, whether the equalization unit of abnormal satisfies re-switching condition is judged, so that it re-enters work when satisfying re-switching condition, to guarantee system efficient operation.

Description

Technical Field

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

[0002] The main problem with existing DC droop modes is that, under low-power operation (taking charging as an example), when the external power requirement is small, the State of Charge (SOC) values ​​of the battery clusters (RACKs) corresponding to the various balancing units within the system may be unbalanced. Therefore, during system charging, a battery cluster RACK corresponding to one balancing unit may have a higher SOC value, causing it to discharge onto the battery cluster RACKs of other balancing units, resulting in internal energy loss and affecting system operation. Summary of the Invention

[0003] This invention provides a method and apparatus for equalization control of an energy storage system, so as to achieve equalization control of the energy storage system, avoid the generation of circulating currents within the system that lead to internal energy consumption, and thus ensure the efficient operation of the system.

[0004] According to one aspect of the present invention, a method for balancing control of an energy storage system is provided, the energy storage system including a battery system management unit, a battery cluster management unit, a balancing unit, a battery system controller, and a local controller; the method for balancing control of the energy storage system includes:

[0005] The system can determine the operating status of the equalization unit in real time, and send a standby command to the equalization unit that is abnormal when the operating status of the equalization unit is abnormal.

[0006] Determine whether the abnormal equalizer unit meets the reswitching conditions. If it does, send a reswitching command to the abnormal equalizer unit.

[0007] Optionally, determining whether the abnormal equalization unit meets the reswitching conditions includes:

[0008] Calculate the average SOC of the system and compare the SOC of the battery clusters in the balancing units that exhibit abnormalities with the average SOC of the system.

[0009] If the preset conditions are met, a reswitching command is sent to the malfunctioning equalization unit; if not, the process returns to compare the SOC value of the battery cluster of the malfunctioning equalization unit with the average SOC value of the system until the preset conditions are met, at which point the return operation stops and a reswitching command is sent to the malfunctioning equalization unit.

[0010] Optionally, if the preset condition is met, a re-switching instruction is sent to the abnormal balancing unit; if not, the operation of comparing the SOC value of the battery cluster of the abnormal balancing unit with the SOC average value of the system is returned until the returning operation is stopped when the preset condition is met, and a re-switching instruction is sent to the abnormal balancing unit, comprising:

[0011] If the first preset condition is met, a re-switching instruction is sent to the abnormal balancing unit; if the first preset condition is not met, it is further judged whether the second preset condition is met, and if the second preset condition is met, a re-switching instruction is sent to the abnormal balancing unit.

[0012] If the second preset condition is not met, the operation of comparing the SOC value of the battery cluster of the abnormal balancing unit with the SOC average value of the system is returned until the returning operation is stopped when the second preset condition is met, and a re-switching instruction is sent to the abnormal balancing unit.

[0013] Optionally, the first preset condition is that the difference between the SOC value of the battery cluster of the abnormal balancing unit and the SOC average value of the system is less than or equal to a preset difference value.

[0014] Optionally, the second preset condition is that the total output power of all normal balancing units does not meet the current external demand power.

[0015] Optionally, the current external demand power is provided by an energy storage converter.

[0016] Optionally, the energy storage system balancing control method further comprises: under high-power operation, real-time regulating the power of the balancing unit; under low-power operation, real-time controlling the operation state of the balancing unit.

[0017] Optionally, the operation state of the balancing unit includes a charging state or a discharging state.

[0018] The abnormal operation state of the balancing unit includes:

[0019] In the charging state, the operation state of the abnormal balancing unit is discharging.

[0020] Or, in the discharging state, the operation state of the abnormal balancing unit is charging.

[0021] Optionally, the method is applied to a direct current droop mode.

[0022] According to another aspect of the present application, an energy storage system balancing control device is provided, which comprises:

[0023] The standby instruction sending module is used for sending a standby instruction to the abnormal balancing unit when the abnormal balancing unit is in an abnormal operating state.

[0024] The re-switching judgment module is used for judging whether the abnormal balancing unit meets a re-switching condition.

[0025] The re-switching instruction sending module is used for sending a re-switching instruction to the abnormal balancing unit if the abnormal balancing unit meets the re-switching condition.

[0026] The technical scheme of the embodiment of the application provides a balancing control method and device for an energy storage system, and the control method comprises the following steps: sending a standby instruction to an abnormal balancing unit when the abnormal balancing unit is in an abnormal operating state; judging whether the abnormal balancing unit meets a re-switching condition, and sending a re-switching instruction to the abnormal balancing unit if the abnormal balancing unit meets the re-switching condition. Through the method, the following effects can be achieved: the system is judged to see whether there is an abnormal balancing unit in an abnormal operating state, and standby control is performed on the abnormal balancing unit in an abnormal operating state in time, so that the abnormal balancing unit can avoid charging and discharging other normal balancing units in the system and internal circulation problems can be avoided; and after standby operation, it is judged whether the abnormal balancing unit meets a re-switching condition, so that the abnormal balancing unit can re-enter work when the re-switching condition is met, thereby ensuring efficient operation of the system. When the abnormal balancing unit meets the re-switching condition, the abnormal balancing unit will not affect other normal balancing units in the system, and internal circulation problems between the balancing units in the system will not occur.

[0027] It should be understood that the content described in this part is not intended to identify key or important features of the embodiments of the application, nor is it used to limit the scope of the application. Other features of the application will become apparent from the following description. BRIEF DESCRIPTION OF DRAWINGS

[0028] In order to more clearly illustrate the technical solutions in the embodiments of the application, the following will briefly introduce the drawings needed to be used in the embodiments. Obviously, the drawings in the following description are only some embodiments of the application, and other drawings can be obtained by those skilled in the art without creative effort.

[0029] Figure 1 is a flow chart of a balancing control method for an energy storage system according to an embodiment of the application;

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

[0031] Figure 3is a flow chart of another energy storage system equalization control method according to an embodiment of the present application;

[0032] Figure 4 is a structural block diagram of an energy storage system according to an embodiment of the present application;

[0033] Figure 5 is a structural schematic diagram of an energy storage system equalization control device according to an embodiment of the present application. DETAILED DESCRIPTION

[0034] In order to make the personnel in the technical field better understand the present application scheme, the technical scheme in the embodiments of the present application will be described clearly and completely below in combination with the drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, not all. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor should belong to the scope of protection of the present application.

[0035] It should be noted that the terms "first", "second" and the like in the specification and claims of the present application and the above-described drawings are used to distinguish similar objects, and do not necessarily indicate a specific order or a chronological sequence. It should be understood that the data thus used can be interchanged under appropriate circumstances, so that the embodiments of the present application described herein can be implemented in an order other than that illustrated or described herein. In addition, the terms "include" and "have" and any variations thereof are intended to cover non-exclusive inclusion, for example, a process, method, system, product or device including a series of steps or units does not have to be limited to those steps or units clearly listed, but can include other steps or units not clearly listed or inherent to these processes, methods, products or devices.

[0036] Figure 1 A flow chart of an energy storage system equalization control method according to an embodiment of the present application is provided. The embodiment can be applicable to the equalization control process of the energy storage system, avoiding the problem of internal loss caused by internal circulation of the system. The method can be executed by an energy storage system equalization control device, which can be realized in the form of hardware and / or software, and can be configured in the server of the energy storage system processing platform. As shown in the figure, the energy storage system includes a battery system management unit, a battery cluster management unit, an equalization unit, a battery system controller and a local controller. Figure 1 The method comprises:

[0037] S110, judging the running state of the equalization unit in real time, and sending a standby instruction to the equalization unit when the running state of the equalization unit is abnormal.

[0038] Wherein, the energy storage system has multiple balancing units, each of which drives a battery cluster RACK. The running state of the energy storage system when running at a small power can be a charging state or a discharging state; similarly, the running state of the balancing unit can be a charging state or a discharging state. Exemplarily, the balancing unit can be a DC / DC converter.

[0039] Assuming that the energy storage system runs in a small power state, for example, in a charging state, normally, the running state of each balancing unit is also in a charging state. When the server detects that the running state of the balancing unit in the energy storage system is in a discharging state, it can be judged that the running state of the balancing unit is abnormal, at this time, the standby instruction is sent to the abnormal balancing unit in time, so that it and the corresponding battery cluster RACK enter the standby state, and the abnormal balancing unit discharges to other normal balancing units in the system is avoided in time, so as to avoid the generation of internal circulation and the increase of internal loss of the system and other problems.

[0040] It should be noted that the number of balancing units detected as abnormal at the same time point or time period can be one or more, no matter how many, the server will send standby instructions to the balancing units with abnormal running states to make them standby, so as to avoid causing internal circulation problems of the system.

[0041] S120, judge whether the abnormal balancing unit meets the re-switching condition, if yes, send the re-switching instruction to the abnormal balancing unit.

[0042] Wherein, the abnormal balancing unit cannot be in standby state all the time, otherwise it will affect the efficient operation of the energy storage system. Therefore, after the standby control of the abnormal balancing unit is made, it is further judged whether the re-switching condition is met, only when the re-switching condition is met, the re-switching can be made to make it re-enter the work, because when the re-switching condition is met, it means that the abnormal balancing unit re-enters the working state without affecting other balancing units in the system and causing internal circulation problems. If the re-switching condition is not met, it means that the abnormal balancing unit re-enters the working state and still affects other balancing units in the system and causes internal circulation problems, so the abnormal balancing unit still needs to be in standby state. Therefore, while avoiding the internal circulation problem of the system, the system can be made to run efficiently as much as possible.

[0043] In the technical scheme of the embodiment, the principle of the energy storage system balancing control method is as follows: firstly, the running state of the balancing unit is judged in real time, and when the running state of the balancing unit is abnormal, a standby instruction is sent to the abnormal balancing unit; then, it is judged whether the abnormal balancing unit meets the re-switching condition, and if yes, a re-switching instruction is sent to the abnormal balancing unit. Therefore, by judging whether the balancing unit with the running state abnormality exists in the system, and by controlling the abnormal balancing unit to be in standby state in time when the running state of the balancing unit is abnormal, the abnormal balancing unit can be prevented from charging or discharging the other normal balancing units in the system, and the internal circulation problem can be avoided; and after the standby operation, it is judged whether the abnormal balancing unit meets the re-switching condition, so that the abnormal balancing unit re-enters the working state when the re-switching condition is met, thereby ensuring efficient operation of the system. When the abnormal balancing unit meets the re-switching condition, the abnormal balancing unit will not affect the other normal balancing units in the system, and the internal circulation problem between the balancing units in the system will not occur.

[0044] Figure 2 The flowchart of another energy storage system balancing control method provided in the embodiment is shown in FIG. 10. As an implementation manner, with reference to FIG. 10, Figure 2 the method comprises the following steps.

[0045] In step 210, the running state of the balancing unit is judged in real time, and when the running state of the balancing unit is abnormal, a standby instruction is sent to the abnormal balancing unit.

[0046] In step 220, the SOC average value of the system is calculated, and the SOC value of the battery cluster of the abnormal balancing unit is compared with the SOC average value of the system.

[0047] In the embodiment, the server can obtain the SOC value of the battery cluster corresponding to each balancing unit. Then, the SOC average value of the system is calculated according to the SOC value of the battery cluster corresponding to each balancing unit. The SOC value of the battery cluster of the abnormal balancing unit is compared with the SOC average value of the system.

[0048] In step 230, it is judged whether the preset condition is met; if yes, step 231 is performed; otherwise, step 232 is performed.

[0049] In step 231, a re-switching instruction is sent to the abnormal balancing unit.

[0050] In the embodiment, the SOC value of the battery cluster of the abnormal balancing unit is compared with the SOC average value of the system. If the preset condition is met, it indicates that the abnormal balancing unit re-enters the working state without affecting the other balancing units in the system and without causing the internal circulation problem, and thus a re-switching instruction can be sent to the abnormal balancing unit to make the abnormal balancing unit re-enter the working state.

[0051] Step 232, return to execute the operation of comparing the SOC value of the battery cluster of the abnormal balancing unit with the SOC average of the system until the preset condition is met, stop the returning operation, and send a re-switching instruction to the abnormal balancing unit.

[0052] The SOC value of the battery cluster of the abnormal balancing unit is compared with the SOC average of the system, and if the preset condition is not met, it indicates that the abnormal balancing unit re-enters the working state and still affects other balancing units in the system, and also causes internal circulation problems. Therefore, the operation of comparing the SOC value of the battery cluster of the abnormal balancing unit with the SOC average of the system is returned to be executed until the preset condition is met, and the returning operation is stopped. As long as the preset condition is met, the abnormal balancing unit can be re-switched to enter the working state.

[0053] In the technical scheme of the embodiment, the principle of the energy storage system balancing control method is as follows: first, the running state of the balancing unit is judged in real time, and when the running state of the balancing unit is abnormal, a standby instruction is sent to the abnormal balancing unit; then, the SOC average of the system is calculated, and the SOC value of the battery cluster of the abnormal balancing unit is compared with the SOC average of the system to determine whether the preset condition is met. If the preset condition is met, a re-switching instruction is sent to the abnormal balancing unit; if the preset condition is not met, the operation of comparing the SOC value of the battery cluster of the abnormal balancing unit with the SOC average of the system is returned to be executed until the preset condition is met, and the returning operation is stopped. Thus, by judging whether the system has an abnormal balancing unit, and when the running state of the balancing unit is abnormal, the abnormal balancing unit is controlled to be in standby state, the abnormal balancing unit is prevented from charging and discharging the other normal balancing units in the system, and internal circulation problems are avoided. After the standby operation, the SOC value of the battery cluster of the abnormal balancing unit is compared with the SOC average of the system, the abnormal balancing unit that meets the preset condition is re-switched, and the operation of comparing the SOC value of the abnormal balancing unit that does not meet the preset condition is re-performed until the abnormal balancing unit is re-switched when the condition is met. Thus, the system can be efficiently operated while avoiding internal circulation problems.

[0054] Figure 3 is another flowchart of an energy storage system balancing control method provided in the embodiment of the application. As an implementation manner, optionally, referring to Figure 3 , the method comprises:

[0055] Step 310, judging the running state of the balancing unit in real time, and sending standby instruction to the balancing unit when the running state of the balancing unit is abnormal.

[0056] Step 320, calculating the SOC average of the system, and comparing the SOC value of the battery cluster of the balancing unit with the SOC average of the system.

[0057] Step 330, judging whether the first preset condition is met, if yes, executing step 331; otherwise, executing step 332.

[0058] Step 331, sending re-switching instruction to the abnormal balancing unit.

[0059] Step 332, judging whether the second preset condition is met, if yes, executing step 331; otherwise, executing step 340.

[0060] Step 340, returning to execute the operation of comparing the SOC value of the battery cluster of the abnormal balancing unit with the SOC average of the system until the second preset condition is met, stopping the returning operation, and sending re-switching instruction to the abnormal balancing unit.

[0061] In the technical scheme of the embodiment, the principle of the energy storage system balancing control method is as follows: firstly, the running state of the balancing unit is judged in real time, and when the running state of the balancing unit is abnormal, a standby instruction is sent to the abnormal balancing unit; then, the SOC average value of the system is calculated, and the SOC value of the battery cluster of the abnormal balancing unit is compared with the SOC average value of the system to determine whether the first preset condition is met, if the first preset condition is met, a re-switching instruction is sent to the abnormal balancing unit. If the first preset condition is not met, it is further determined whether the second preset condition is met, if the second preset condition is met, a re-switching instruction is sent to the abnormal balancing unit. If the second preset condition is not met, the operation of comparing the SOC value of the battery cluster of the abnormal balancing unit with the SOC average value of the system is returned until the second preset condition is met, the operation of returning is stopped, and a re-switching instruction is sent to the abnormal balancing unit. Therefore, by judging whether the system has a balancing unit with an abnormal running state, and by controlling the abnormal balancing unit in standby mode when the balancing unit has an abnormal running state, the abnormal balancing unit can be prevented from charging and discharging other normal balancing units in the system, and internal circulation problems can be avoided. After the standby operation, the SOC value of the battery cluster of the abnormal balancing unit is compared with the SOC average value of the system, the abnormal balancing unit meeting the first preset condition and the second preset condition is re-switched, and the SOC value comparison operation of the abnormal balancing unit not meeting the second preset condition is performed again until the second preset condition is met. Therefore, the system can be efficiently operated while avoiding internal circulation problems.

[0062] As a specific implementation, optionally, the first preset condition is that the difference between the SOC value of the battery cluster of the abnormal balancing unit and the SOC average value of the system is less than or equal to a preset difference value.

[0063] The preset difference value is an error range difference value, which is usually small in value, and the specific value can be set according to actual conditions, which is not limited here.

[0064] Specifically, if the difference between the SOC value of the battery cluster of the abnormal balancing unit and the SOC average value of the system is less than or equal to the preset difference value, the SOC value of the battery cluster of the abnormal balancing unit can be considered equal to the SOC average value of the system within the error allowable range, which indicates that the abnormal balancing unit will not charge and discharge other normal balancing units in the system within the error allowable range, i.e., internal circulation problems will not occur, and the abnormal balancing unit can be re-switched to the working state, thereby ensuring efficient operation of the system.

[0065] As a specific implementation, optionally, the second preset condition is that the sum of output powers of all normal balancing units does not meet the current external demand power.

[0066] Specifically, if the difference between the SOC value of the battery cluster of the abnormal balancing unit and the average SOC value of the system is greater than a preset difference value, it indicates that the SOC value of the battery cluster of the abnormal balancing unit is greatly different from the average SOC value of the system, and at this time, the current external demand power needs to be combined to further determine whether it is suitable to be switched and whether the switching will affect other normal balancing units of the system. Further, it is determined whether the sum of output powers of all remaining normal balancing units meets the current external demand power. If the sum of output powers of all remaining normal balancing units cannot meet the current external demand power, it indicates that the external demand power is relatively large at this time, and all remaining normal balancing units of the system cannot meet the external demand power requirement. At this time, the abnormal balancing unit is sent a re-switching instruction to re-switch into work, and it will no longer have surplus power to charge and discharge other normal balancing units inside, but will output externally together with other normal balancing units to meet the current external demand power.

[0067] If the sum of output powers of all remaining normal balancing units can meet the current external demand power, it indicates that the external demand power is relatively small at this time, and all remaining normal balancing units of the system can meet the current external demand power requirement. At this time, if the abnormal balancing unit re-switches into work, it will still cause internal circulating current problems, and therefore, it still needs to be on standby, and the operation of comparing the SOC value of the battery cluster of the abnormal balancing unit with the average SOC value of the system is continued to be returned until the sum of output powers of all remaining normal balancing units cannot meet the current external demand power, and the re-switching instruction is sent to the abnormal balancing unit. Thus, the internal circulating current problem of the system is avoided, and the overall operation efficiency of the system is improved.

[0068] Optionally, the current external demand power is provided by a power conversion system.

[0069] The power conversion system (PCS) determines the current external demand power according to the output power of the external power grid and the real-time SOC value of the energy storage system.

[0070] Optionally, the operation state of the balancing unit includes a charging state or a discharging state.

[0071] The operation state of each balancing unit can be in the charging state or the discharging state when the energy storage system is in the small power state.

[0072] Optionally, the abnormal operation state of the balancing unit includes:

[0073] When the operation state is the charging state, the operation state of the abnormal balancing unit is the discharging state.

[0074] Or, when the operation state is the discharging state, the operation state of the abnormal balancing unit is the charging state.

[0075] Specifically, assuming that the energy storage system is in the small power charging state, the normal operation state of the balancing unit is the charging state, and when the operation state of the balancing unit is the discharging state, it indicates that the operation state of the balancing unit is abnormal. Similarly, assuming that the energy storage system is in the small power discharging state, the normal operation state of the balancing unit is the discharging state, and when the operation state of the balancing unit is the charging state, it indicates that the operation state of the balancing unit is abnormal.

[0076] Figure 4 is a structural block diagram of an energy storage system provided by an embodiment of the present application. Optionally, the energy storage system balancing control method is applied to a direct current droop mode.

[0077] The direct current droop mode is: Figure 4, DC / DC side to start with constant bus voltage, for the system to establish bus voltage, after the bus voltage is stable, the energy storage converter (Power Conversion System, PCS) with constant power mode operation, according to the system demand to adjust the power value size. In the process of operation, the local controller (Local Control, LC) by calculating the system SOC value, adjust the DC / DC power size; in the existing mode, the bottom DC / DC itself according to the droop coefficient output, no need to give power instruction, can greatly balance the SOC value between systems, effectively reduces the circulation between DC / DC. Specifically, the battery management unit (Battery Management Unit, BMU) collects cell voltage, temperature and other information uploaded to the battery cluster management unit (Battery Cluster Management Unit, CMU), CMU collects system cell information and transmits to the battery system controller (Battery system controller, BSC), BSC uploads information to LC. Among them, each DC / DC with single battery cluster RACK; in the process of operation, by LC according to the system SOC average of each DC / DC power scheduling, to ensure that the SOC value of the system remains relatively balanced, to avoid the barrel effect of the battery.

[0078] Optionally, in the high-power operation, real-time regulation and control of the balancing unit power; in the small power operation, real-time control of the balancing unit operating state.

[0079] Specifically, when the energy storage system is operated at high power, the SOC average of the system is calculated, and the SOC value of each balancing unit battery cluster is compared with the SOC average of the system. Taking the SOC value of each battery cluster as the reference, the power value of each balancing unit is adjusted to balance the SOC value between the battery clusters of the system, thereby avoiding the barrel effect of the system. Thus, the balancing control of the energy storage system can be realized, and the working state of the balancing unit can be controlled in real time under small power operation, avoiding the circulation of the system to cause energy loss, thereby ensuring the efficient operation of the system.

[0080] Figure 5 The structure diagram of the energy storage system balancing control device provided in the embodiment of the application is shown in the figure. Figure 5 As shown in the figure, the device 100 comprises:

[0081] The standby instruction sending module 10 is used for real-time judgment of the operating state of the balancing unit, and sends standby instructions to the balancing unit when the operating state of the balancing unit is abnormal.

[0082] The re-switching judgment module 20 is configured to judge whether the abnormal balancing unit meets a re-switching condition.

[0083] The re-switching instruction sending module 30 is configured to send a re-switching instruction to the abnormal balancing unit if the re-switching condition is met.

[0084] The technical scheme of the embodiment provides a balancing control device for an energy storage system, which comprises a standby instruction sending module configured to judge the running state of the balancing unit in real time and send a standby instruction to the abnormal balancing unit when the running state of the balancing unit is abnormal; a re-switching judgment module configured to judge whether the abnormal balancing unit meets a re-switching condition; and a re-switching instruction sending module configured to send a re-switching instruction to the abnormal balancing unit if the re-switching condition is met. The device can realize the following: judging whether the system has an abnormal balancing unit, and performing standby control on the abnormal balancing unit in time when the running state of the balancing unit is abnormal, so as to avoid the abnormal balancing unit from charging and discharging other normal balancing units in the system and to avoid the internal circulation problem. After standby operation, the device judges whether the abnormal balancing unit meets a re-switching condition, so that the abnormal balancing unit re-enters the working state when the re-switching condition is met, thereby ensuring efficient operation of the system. When the abnormal balancing unit meets the re-switching condition, the abnormal balancing unit will not affect other normal balancing units in the system, and the internal circulation problem between the balancing units in the system will not occur.

[0085] Optionally, the re-switching judgment module 20 comprises:

[0086] The SOC average value calculation unit is configured to calculate the SOC average value of the system.

[0087] The SOC value comparison unit is configured to compare the SOC value of the battery cluster of the abnormal balancing unit with the SOC average value of the system.

[0088] The preset condition judgment unit is configured to send a re-switching instruction to the abnormal balancing unit if a preset condition is met, and to return to the operation of comparing the SOC value of the battery cluster of the abnormal balancing unit with the SOC average value of the system until the preset condition is met and the re-switching instruction is sent to the abnormal balancing unit.

[0089] Optionally, the preset condition judgment unit is further configured to:

[0090] If the first preset condition is met, a re-switching instruction is sent to the abnormal balancing unit; if the first preset condition is not met, it is further judged whether the second preset condition is met, if the second preset condition is met, a re-switching instruction is sent to the abnormal balancing unit;

[0091] If the second preset condition is not met, the operation of comparing the SOC value of the battery cluster of the abnormal balancing unit with the SOC average value of the system is returned until the second preset condition is met, the returning operation is stopped, and a re-switching instruction is sent to the abnormal balancing unit.

[0092] Optionally, the first preset condition is that the difference between the SOC value of the battery cluster of the abnormal balancing unit and the SOC average value of the system is less than or equal to a preset difference value.

[0093] Optionally, the second preset condition is that the total output power of all normal balancing units does not meet the current external demand power.

[0094] Optionally, the current external demand power is provided by the energy storage converter.

[0095] Optionally, the energy storage system balancing control method further comprises: in a high-power operation, the power of the balancing unit is real-time regulated; in a low-power operation, the operation state of the balancing unit is real-time controlled.

[0096] Optionally, the operation state of the balancing unit includes a charging state or a discharging state.

[0097] The abnormal operation state of the balancing unit includes:

[0098] In the charging state, the operation state of the abnormal balancing unit is discharging.

[0099] Or, in the discharging state, the operation state of the abnormal balancing unit is charging.

[0100] Optionally, the SOC value of the battery cluster of the abnormal balancing unit is greater than the SOC value of the battery cluster of other normal balancing units.

[0101] Optionally, the energy storage system balancing control method is applied to a direct-current droop mode.

[0102] The energy storage system balancing control device provided by the embodiment of the application can execute the energy storage system balancing control method provided by any embodiment of the application, and has the corresponding function modules and beneficial effects of the execution method.

[0103] It should be understood that the various forms of flow shown above can be used to reorder, add, or remove steps. For example, the steps recited in the present application can be performed in parallel, in series, or in a different order, as long as the desired results of the technical solutions of the present application can be achieved, which are not limited herein.

[0104] The above detailed description does not constitute a limitation on the protection scope of the present application. Those skilled in the art should understand that various modifications, combinations, sub-combinations, and substitutions can be made according to design requirements and other factors. Any modifications, equivalent replacements, and improvements made within the spirit and principles of the present application shall be included in the protection scope of the present application.

Claims

1. A method for equalization control of an energy storage system, characterized by, The energy storage system comprises a battery system management unit, a battery cluster management unit, an equalization unit, a battery system controller and a local controller; wherein each equalization unit drives a battery cluster; the control method comprises: Real-time determination of the operating state of the equalization unit, when the operating state of the equalization unit is abnormal, a standby instruction is sent to the abnormal equalization unit, so that the abnormal equalization unit and the corresponding battery cluster enter a standby state, and the other normal equalization units operate normally; Determine whether the abnormal equalization unit meets the re-switching condition, and if so, send a re-switching instruction to the abnormal equalization unit.

2. The energy storage system equalization control method of claim 1, wherein, The determination of whether the abnormal equalization unit meets the re-switching condition comprises: Calculate the SOC average value of the system, and compare the SOC value of the battery cluster of the abnormal equalization unit with the SOC average value of the system; If the preset condition is met, a re-switching instruction is sent to the abnormal equalization unit; if not, return to execute the operation of comparing the SOC value of the battery cluster of the abnormal equalization unit with the SOC average value of the system until the preset condition is met, stop returning operation, and send a re-switching instruction to the abnormal equalization unit.

3. The energy storage system equalization control method of claim 2, wherein, If the preset condition is met, a re-switching instruction is sent to the abnormal equalization unit; if not, return to execute the operation of comparing the SOC value of the battery cluster of the abnormal equalization unit with the SOC average value of the system until the preset condition is met, stop returning operation, and send a re-switching instruction to the abnormal equalization unit. If the first preset condition is met, a re-switching instruction is sent to the abnormal equalization unit; if the first preset condition is not met, further determine whether the second preset condition is met, and if the second preset condition is met, a re-switching instruction is sent to the abnormal equalization unit; If the second preset condition is not met, return to execute the operation of comparing the SOC value of the battery cluster of the abnormal equalization unit with the SOC average value of the system until the second preset condition is met, stop returning operation, and send a re-switching instruction to the abnormal equalization unit.

4. The energy storage system equalization control method of claim 3, wherein, The first preset condition is that the difference between the SOC value of the battery cluster of the abnormal equalization unit and the SOC average value of the system is less than or equal to a preset difference value.

5. The energy storage system equalization control method of claim 3, wherein, The second preset condition is that the total output power of all normal equalization units does not meet the current external demand power.

6. The energy storage system equalization control method of claim 5, wherein, The current external demand power is provided by the energy storage converter.

7. The energy storage system equalization control method of claim 1, wherein, Further comprising: Real-time regulation of the power of the equalization unit under high-power operation; Real-time control of the operating state of the equalization unit under low-power operation.

8. The energy storage system equalization control method of claim 1, wherein, The operating state of the equalization unit includes a charging state or a discharging state; The abnormal operating state of the equalization unit includes: When the operating state is a charging state, the operating state of the abnormal equalization unit is discharging; Or, when the operating state is a discharging state, the operating state of the abnormal equalization unit is charging.

9. The energy storage system equalization control method of claim 1, wherein, The method is applied to a direct current droop mode.

10. An energy storage system equalization control device, comprising: Comprise: The standby instruction sending module is configured to judge the running state of the balancing unit in real time, and send a standby instruction to the balancing unit that has an abnormal running state, so that the balancing unit and the corresponding battery cluster enter a standby state, and other normal balancing units run normally; each balancing unit drives a battery cluster; The re-switching judgment module is configured to judge whether the balancing unit that has an abnormal running state meets a re-switching condition; The re-switching instruction sending module is configured to send a re-switching instruction to the balancing unit that has an abnormal running state if the re-switching condition is met.

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