Equalization Method, Device, Electronic Device and Storage Medium for Energy Storage System

Abstract

The present invention provides a method, device, electronic device and storage medium for balancing an energy storage system, relating to the technical field of energy storage balancing, including: obtaining the static voltages of multiple battery clusters respectively and the standby time corresponding to the energy storage system; performing a difference operation on the static voltages of the multiple battery clusters pairwise to determine the static voltage differences between multiple clusters; determining the balancing mode of the energy storage system based on the static voltage differences between multiple clusters and the standby time; if the balancing mode is the balancing maintenance mode, determining the lowest voltage and the highest voltage among the static voltages of the multiple battery clusters respectively; connecting the lowest battery cluster corresponding to the lowest voltage and the highest battery cluster corresponding to the highest voltage through a balancing circuit, and performing balancing adjustment on the lowest battery cluster and the highest battery cluster based on a pre-set balancing strategy. In this way, the balancing among multiple battery clusters of the energy storage system is achieved without delaying the normal operation of the energy storage system, and the service life of the energy storage system is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of energy storage balancing, and in particular, to a balancing method, device, electronic device and storage medium for an energy storage system. Background Art

[0002] Balancing has always been a pain point in energy storage systems. Balancing the energy storage system can not only improve the lifespan of the energy storage system, but also avoid the circulating current impact caused by excessive pressure difference and the resulting system failure. Therefore, how to achieve the balance between multiple battery clusters in the energy storage system is an urgent problem to be solved currently. Summary of the Invention

[0003] In view of this, the purpose of the present invention is to provide a balancing method, device, electronic device and storage medium for an energy storage system, which realizes the balance between multiple battery clusters in the energy storage system without delaying the normal operation of the energy storage system, improves the lifespan of the energy storage system, and avoids the circulating current impact caused by excessive pressure difference and the resulting system failure.

[0004] In the first aspect, an embodiment of the present invention provides a balancing method for an energy storage system. The energy storage system includes multiple battery clusters. The method includes: obtaining the static voltage of each of the multiple battery clusters and the standby time corresponding to the energy storage system; performing a difference operation on the static voltages of each of the multiple battery clusters in pairs to determine the static pressure difference between multiple clusters; determining the balancing mode of the energy storage system based on the static pressure difference between multiple clusters and the standby time; if the balancing mode is the balancing maintenance mode, determining the lowest voltage and the highest voltage among the static voltages of each of the multiple battery clusters; connecting the lowest battery cluster corresponding to the lowest voltage and the highest battery cluster corresponding to the highest voltage through a balancing circuit, and performing balancing adjustment on the lowest battery cluster and the highest battery cluster based on a pre-set balancing strategy.

[0005] In a preferred embodiment of the present invention, the determining the balancing mode of the energy storage system based on the static pressure difference between multiple clusters and the standby time includes: comparing the static pressure differences between multiple clusters with a pre-set pressure difference threshold respectively; if there is a static pressure difference between clusters that meets the pressure difference threshold, comparing the standby time with a pre-set time threshold; if the standby time is greater than the pre-set time threshold, the balancing mode is the balancing maintenance mode; if the standby time is less than or equal to the time threshold, the balancing mode is the balancing operation mode; if there is no static pressure difference between clusters that meets the pressure difference threshold, the balancing mode is the balancing static mode.

[0006] In a preferred embodiment of the present invention, after determining the equalization mode of the energy storage system based on the static pressure difference between multiple clusters and the standby time, the method further includes: if the equalization mode is the equalization operation mode, performing an average processing on the static voltages of the multiple battery clusters to obtain an average cluster voltage; comparing the static voltages of the multiple battery clusters with the average cluster voltage respectively to determine the target battery clusters with static voltages less than the average cluster voltage; connecting the multiple battery clusters in pairs through an equalization circuit, and performing equalization adjustment on the target battery clusters based on a preset equalization strategy.

[0007] In a preferred embodiment of the present invention, the above-mentioned performing equalization adjustment on the target battery clusters based on a preset equalization strategy includes: the target battery clusters requesting a first voltage and a first current from the equalization circuit; the equalization circuit performing equalization adjustment on the target battery clusters through the first voltage and the first current.

[0008] In a preferred embodiment of the present invention, the above-mentioned connecting the lowest battery cluster corresponding to the lowest voltage and the highest battery cluster corresponding to the highest voltage through the equalization circuit, and performing equalization adjustment on the lowest battery cluster and the highest battery cluster based on a preset equalization strategy includes: connecting the lowest battery cluster corresponding to the lowest voltage and the highest battery cluster corresponding to the highest voltage through the equalization circuit, and the lowest battery cluster requesting a second voltage and a second current from the equalization circuit; the equalization circuit performing equalization adjustment on the lowest battery cluster through the second voltage and the second current until the static pressure difference between the lowest battery cluster and the highest battery cluster meets the preset static pressure difference threshold, and then disconnecting the equalization circuit.

[0009] In a preferred embodiment of the present invention, after disconnecting the equalization circuit, the method further includes: determining again the lowest voltage and the highest voltage among the static voltages of the multiple battery clusters to equalize the energy storage system until the static pressure differences between multiple clusters all meet the static pressure difference threshold.

[0010] In a preferred embodiment of the present invention, the equalization circuit includes a DC-DC converter, and DC-DC converters are connected between multiple battery clusters. During equalization adjustment, the corresponding DC-DC converter is connected based on the equalization strategy.

[0011] In a second aspect, an embodiment of the present invention further provides an equalization device for an energy storage system. The energy storage system includes a plurality of battery clusters. The device includes: an acquisition module, configured to acquire the static voltages of the plurality of battery clusters respectively and the standby time corresponding to the energy storage system; an inter-cluster static voltage difference determination module, configured to perform a difference operation on the static voltages of the plurality of battery clusters pairwise to determine a plurality of inter-cluster static voltage differences; an equalization mode determination module, configured to determine the equalization mode of the energy storage system based on the plurality of inter-cluster static voltage differences and the standby time; a voltage determination module, configured to, if the equalization mode is an equalization maintenance mode, determine the lowest voltage and the highest voltage among the static voltages of the plurality of battery clusters respectively; and an energy storage system equalization module, configured to connect the lowest battery cluster corresponding to the lowest voltage and the highest battery cluster corresponding to the highest voltage through an equalization circuit based on a pre-set equalization strategy to perform equalization of the energy storage system.

[0012] In a third aspect, an embodiment of the present invention further provides an electronic device, including a processor and a memory. The memory stores computer-executable instructions that can be executed by the processor. The processor executes the computer-executable instructions to implement the equalization method for the energy storage system in the first aspect above.

[0013] In a fourth aspect, an embodiment of the present invention further provides a computer-readable storage medium. The computer-readable storage medium stores computer-executable instructions. When the computer-executable instructions are called and executed by a processor, the computer-executable instructions cause the processor to implement the equalization method for the energy storage system in the first aspect above.

[0014] The embodiments of the present invention bring the following beneficial effects:

[0015] The embodiments of the present invention provide an equalization method, device, electronic device and storage medium for an energy storage system. By acquiring the static voltages of the plurality of battery clusters respectively and the standby time corresponding to the energy storage system; performing a difference operation on the static voltages of the plurality of battery clusters pairwise to determine a plurality of inter-cluster static voltage differences; determining the equalization mode of the energy storage system based on the plurality of inter-cluster static voltage differences and the standby time; if the equalization mode is an equalization maintenance mode, determining the lowest voltage and the highest voltage among the static voltages of the plurality of battery clusters respectively; connecting the lowest battery cluster corresponding to the lowest voltage and the highest battery cluster corresponding to the highest voltage through an equalization circuit, and performing equalization adjustment on the lowest battery cluster and the highest battery cluster based on a pre-set equalization strategy. In this way, the equalization among multiple battery clusters of the energy storage system is realized without delaying the normal operation of the energy storage system, the service life of the energy storage system is improved, and the circulating current influence caused by too large voltage difference and the resulting system failure are avoided.

[0016] Other features and advantages of the present disclosure will be described in the following description, or some features and advantages can be inferred from the description without doubt, or can be known by implementing the above technologies of the present disclosure.

[0017] To make the above objects, features, and advantages of the present disclosure more obvious and understandable, the following provides preferred embodiments in conjunction with the accompanying drawings and describes them in detail as follows. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the following will briefly introduce the drawings required for use in the description of the specific embodiments or the prior art. Obviously, the drawings in the following description are some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0019] Figure 1 It is a flowchart of an equalization method for an energy storage system provided by an embodiment of the present invention;

[0020] Figure 2 It is a schematic diagram of a charge-discharge equalization circuit for an energy storage system provided by an embodiment of the present invention;

[0021] Figure 3 It is a flowchart of another equalization method for an energy storage system provided by an embodiment of the present invention;

[0022] Figure 4 It is a schematic diagram of the structure of an equalization device for an energy storage system provided by an embodiment of the present invention;

[0023] Figure 5 It is a schematic diagram of the structure of an electronic device provided by an embodiment of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0024] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the following will clearly and completely describe the technical solutions of the present invention with reference to the accompanying drawings. Obviously, the described embodiments are some, but not all, of the embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art without creative efforts based on the embodiments of the present invention fall within the scope of protection of the present invention.

[0025] Equalization has always been a pain point for energy storage systems. Equalizing the energy storage system can not only improve the lifespan of the energy storage system but also avoid the circulating current impact caused by excessive pressure difference and prevent the system from malfunctioning. Therefore, how to achieve equalization among multiple battery clusters in an energy storage system is an urgent problem to be solved currently.

[0026] Based on this, an equalization method, device, electronic device, and storage medium for an energy storage system provided by an embodiment of the present invention can obtain the static voltages of multiple battery clusters and the standby time corresponding to the energy storage system; subtract the static voltages of multiple battery clusters pairwise to determine the static voltage differences between multiple clusters; determine the equalization mode of the energy storage system based on the static voltage differences between multiple clusters and the standby time; if the equalization mode is the equalization maintenance mode, then determine the lowest voltage and the highest voltage among the static voltages of multiple battery clusters; connect the lowest battery cluster corresponding to the lowest voltage and the highest battery cluster corresponding to the highest voltage through an equalization circuit, and perform equalization adjustment on the lowest battery cluster and the highest battery cluster based on a preset equalization strategy. In this way, the equalization between multiple battery clusters of the energy storage system is achieved without delaying the normal operation of the energy storage system, the service life of the energy storage system is improved, and the circulating current influence caused by too large voltage difference and the resulting system inoperability are avoided.

[0027] To facilitate the understanding of this embodiment, first, a detailed introduction to an equalization method for an energy storage system disclosed by an embodiment of the present invention will be given.

[0028] Embodiment 1

[0029] An embodiment of the present invention provides an equalization method for an energy storage system. Figure 1 This is a flowchart of an equalization method for an energy storage system provided by an embodiment of the present invention. As Figure 1 shown, the equalization method for this energy storage system may include the following steps:

[0030] Step S101, obtain the static voltages of multiple battery clusters and the standby time corresponding to the energy storage system.

[0031] Among them, the static voltage is the voltage of the battery cluster when it is not performing charge and discharge operations, and the standby time is the duration during which the energy storage system does not perform charge and discharge operations. The standby time can be determined according to the charge and discharge tasks of the energy storage system.

[0032] Step S102, subtract the static voltages of multiple battery clusters pairwise to determine the static voltage differences between multiple clusters.

[0033] For example, there are three battery clusters, namely battery cluster A, battery cluster B, and battery cluster C. Then, subtracting the static voltages of multiple battery clusters pairwise means subtracting the static voltage of battery cluster A from the static voltage of battery cluster B to obtain the corresponding static voltage difference between clusters, subtracting the static voltage of battery cluster A from the static voltage of battery cluster C to obtain the corresponding static voltage difference between clusters, and subtracting the static voltage of battery cluster B from the static voltage of battery cluster C to obtain the corresponding static voltage difference between clusters.

[0034] Step S103: Determine the equalization mode of the energy storage system based on the static pressure differences between multiple clusters and the standby time.

[0035] Among them, the equalization mode can include an equalization maintenance mode, an equalization operation mode, and an equalization static mode. The equalization maintenance mode is a mode carried out under the conditions of sufficient standby time and equalization requirements. In this mode, equalization is performed cluster by cluster, with the highest fineness. The equalization operation mode is a mode carried out under the conditions of insufficient standby time but with equalization requirements. In this mode, equalization is performed based on the determined average cluster voltage and the static voltage of the battery cluster, with a slightly lower fineness than the equalization maintenance mode. The equalization static mode is a mode carried out under the condition of no equalization requirements, and usually no equalization control is performed.

[0036] Step S104: If the equalization mode is the equalization maintenance mode, determine the lowest voltage and the highest voltage among the static voltages of the multiple battery clusters.

[0037] Among them, by determining the lowest voltage and the highest voltage, equalization can be preferentially performed on these two clusters of voltages, greatly improving the consistency of the system static voltage.

[0038] Step S105: Connect the lowest battery cluster corresponding to the lowest voltage and the highest battery cluster corresponding to the highest voltage through the equalization circuit, and perform equalization adjustment on the lowest battery cluster and the highest battery cluster based on the preset equalization strategy.

[0039] Among them, the equalization circuit includes a DC-DC converter. DC-DC converters are connected between multiple battery clusters. When performing equalization adjustment, the corresponding DC-DC converter is connected based on the equalization strategy.

[0040] For easy understanding, Figure 2 FIG. is a schematic diagram of the charge and discharge equalization circuit of an energy storage system provided by an embodiment of the present invention. As Figure 2 shown, the charge and discharge equalization circuit includes an equalization circuit and a system charge and discharge main circuit. The DC-DC converter in the equalization circuit is connected to the high-voltage box, and the high-voltage box is connected to the battery cluster (PACK). Figure 2 In the figure, n battery cluster branches are taken as an example. When performing equalization adjustment, the on-off of the DC-DC converter between battery clusters is controlled through the equalization strategy. When the energy storage system is working normally, it is connected to the PCS (Power Conversion System, energy storage converter) and the power grid by closing the circuit breaker to work.

[0041] The equalization method of the energy storage system provided by the embodiment of the present invention can obtain the static voltage of each of multiple battery clusters and the standby time corresponding to the energy storage system; perform a difference operation on the static voltages of each of the multiple battery clusters in pairs to determine the static voltage difference between multiple clusters; determine the equalization mode of the energy storage system based on the static voltage difference between multiple clusters and the standby time; if the equalization mode is the equalization maintenance mode, determine the lowest voltage and the highest voltage among the static voltages of each of the multiple battery clusters; connect the lowest battery cluster corresponding to the lowest voltage and the highest battery cluster corresponding to the highest voltage through an equalization circuit, and perform equalization adjustment on the lowest battery cluster and the highest battery cluster based on a preset equalization strategy. In this way, the equalization among multiple battery clusters of the energy storage system is achieved without delaying the normal operation of the energy storage system, the service life of the energy storage system is improved, and the circulating current influence caused by too large a voltage difference and the resulting system inoperability are avoided.

[0042] Embodiment 2

[0043] The embodiment of the present invention also provides another equalization method for the energy storage system; this method is implemented on the basis of the method of the above embodiment.

[0044] Figure 3 is a flowchart of another equalization method for the energy storage system provided by the embodiment of the present invention, as Figure 3 shown, the equalization method of this energy storage system may include the following steps:

[0045] Step S201, obtain the static voltage of each of multiple battery clusters and the standby time corresponding to the energy storage system.

[0046] Step S202, perform a difference operation on the static voltages of each of the multiple battery clusters in pairs to determine the static voltage difference between multiple clusters.

[0047] Among them, step S201 and step S202 are similar to the above step S101 and step S102, and will not be elaborated here.

[0048] Step S203, determine the equalization mode of the energy storage system based on the static voltage difference between multiple clusters and the standby time.

[0049] Specifically, determining the operation mode of the energy storage system based on the static voltage difference between multiple clusters and the standby time may include: comparing the static voltage differences between multiple clusters with a preset voltage difference threshold respectively; if there is a static voltage difference between clusters that meets the voltage difference threshold, then compare the standby time with a preset time threshold; if the standby time is greater than the preset time threshold, the equalization mode is the equalization maintenance mode; if the standby time is less than or equal to the time threshold, the equalization mode is the equalization operation mode; if there is no static voltage difference between clusters that meets the voltage difference threshold, the equalization mode is the equalization static mode.

[0050] Among them, the pressure difference threshold can be 20V. If it is greater than 20V, it is considered to meet the pressure difference threshold. The time threshold can be 30 minutes. If it is greater than 30 minutes, it is considered to meet the time threshold.

[0051] Among them, for the equalization maintenance mode, the pressure difference threshold and the time threshold can be further divided and matched. For example, when the pressure difference threshold range is (20V, 40V), the time threshold is greater than 30 minutes. When the pressure difference is above 40V, the time threshold is greater than 60 minutes.

[0052] Step S204: If the equalization mode is the equalization operation mode, then perform an averaging process on the static voltages of multiple battery clusters to obtain the average cluster voltage.

[0053] For example, there are three battery clusters, namely battery cluster A, battery cluster B, and battery cluster C. The sum of the static voltages of battery cluster A, battery cluster B, and battery cluster C is divided by 3 to obtain the average cluster voltage.

[0054] Step S205: Compare the static voltages of multiple battery clusters with the average cluster voltage respectively to determine the target battery clusters with static voltages lower than the average cluster voltage.

[0055] Among them, the target battery clusters with static voltages lower than the average cluster voltage need to be adjusted for equalization. For the battery clusters with static voltages higher than the average cluster voltage, the high-voltage box of such battery clusters can meet the external discharge at this time.

[0056] Step S206: Connect multiple battery clusters in pairs through an equalization circuit and perform equalization adjustment on the target battery clusters based on a pre-set equalization strategy.

[0057] Specifically, performing equalization adjustment on the target battery clusters based on a pre-set equalization strategy may include: the target battery clusters request a first voltage and a first current from the equalization circuit; the equalization circuit performs equalization adjustment on the target battery clusters through the first voltage and the first current.

[0058] Among them, the first voltage can be 20V, and the first current can be 30A. It should be noted that the first voltage and the first current can be adjusted according to the magnitude of the static pressure difference between clusters, and no specific limitation is made here.

[0059] Step S207: If the equalization mode is the equalization maintenance mode, then determine the lowest voltage and the highest voltage among the static voltages of multiple battery clusters.

[0060] Among them, Step S207 is similar to Step S104, and details are not elaborated here.

[0061] Step S208: Connect the lowest battery cluster corresponding to the lowest voltage and the highest battery cluster corresponding to the highest voltage through an equalization circuit, and perform equalization adjustment on the lowest battery cluster and the highest battery cluster based on a pre-set equalization strategy.

[0062] Specifically, connect the lowest battery cluster corresponding to the lowest voltage and the highest battery cluster corresponding to the highest voltage through an equalization circuit. The lowest battery cluster requests a second voltage and a second current from the equalization circuit. The equalization circuit performs equalization adjustment on the lowest battery cluster through the second voltage and the second current until the inter-cluster static pressure difference between the lowest battery cluster and the highest battery cluster meets the pre-set static pressure difference threshold, and then disconnect the equalization circuit. Determine the lowest voltage and the highest voltage among the static voltages of the multiple battery clusters again to equalize the energy storage system until all the inter-cluster static pressure differences meet the static pressure difference threshold.

[0063] Among them, the second voltage can be 20V, the second current can be 30A, and the static pressure difference threshold can be 15V. It should be noted that the second voltage and the second current can be adjusted according to the magnitude of the inter-cluster static pressure difference, and are not limited here.

[0064] Among them, after determining the highest voltage and the lowest voltage, connect the lowest battery cluster corresponding to the highest voltage and the highest battery cluster corresponding to the highest voltage through an equalization circuit. At the same time, the lowest battery cluster requests a second voltage and a second current from the corresponding equalization circuit for equalization maintenance until the inter-cluster static pressure difference between the highest battery cluster and the lowest battery cluster is less than the static pressure difference threshold, and then re-determine the new highest voltage and the lowest voltage and repeat the above operations until all the inter-cluster static pressure differences are less than the static pressure difference threshold. This greatly improves the equalization fineness.

[0065] Embodiment 3

[0066] Corresponding to the above method embodiment, an equalization device for an energy storage system is provided in an embodiment of the present invention. Figure 4 It is a schematic structural diagram of an equalization device for an energy storage system provided in an embodiment of the present invention, as Figure 4 shown. The equalization device for the energy storage system may include:

[0067] An acquisition module 301, configured to acquire the static voltages of multiple battery clusters and the standby time corresponding to the energy storage system.

[0068] An inter-cluster static pressure difference determination module 302, configured to perform a difference operation on the static voltages of multiple battery clusters pairwise to determine multiple inter-cluster static pressure differences.

[0069] An equalization mode determination module 303, configured to determine the equalization mode of the energy storage system based on multiple inter-cluster static pressure differences and the standby time.

[0070] A voltage determination module 304, configured to determine the lowest voltage and the highest voltage among the rest voltages of multiple battery clusters if the equalization mode is an equalization maintenance mode.

[0071] An energy storage system equalization module 305, configured to connect the lowest battery cluster corresponding to the lowest voltage and the highest battery cluster corresponding to the highest voltage through an equalization loop based on a pre-set equalization strategy, so as to perform equalization of the energy storage system.

[0072] The equalization device of the energy storage system provided by the embodiment of the present invention can obtain the rest voltages of multiple battery clusters and the standby time corresponding to the energy storage system; perform a difference operation on the rest voltages of multiple battery clusters in pairs to determine the rest voltage difference between multiple clusters; determine the equalization mode of the energy storage system based on the rest voltage difference between multiple clusters and the standby time; if the equalization mode is an equalization maintenance mode, determine the lowest voltage and the highest voltage among the rest voltages of multiple battery clusters; connect the lowest battery cluster corresponding to the lowest voltage and the highest battery cluster corresponding to the highest voltage through an equalization loop, and perform equalization adjustment on the lowest battery cluster and the highest battery cluster based on a pre-set equalization strategy. In this way, equalization among multiple battery clusters of the energy storage system is realized without delaying the normal operation of the energy storage system, the service life of the energy storage system is improved, and the circulating current influence caused by too large a voltage difference and the resulting system inoperability are avoided.

[0073] In some embodiments, the equalization mode determination module is further configured to compare the rest voltage differences between multiple clusters with a pre-set voltage difference threshold respectively; if there is a rest voltage difference between clusters that meets the voltage difference threshold, compare the standby time with a pre-set time threshold; if the standby time is greater than the pre-set time threshold, the equalization mode is an equalization maintenance mode; if the standby time is less than or equal to the time threshold, the equalization mode is an equalization operation mode; if there is no rest voltage difference between clusters that meets the voltage difference threshold, the equalization mode is an equalization static mode.

[0074] In some embodiments, the energy storage system equalization module is further configured to, if the equalization mode is an equalization operation mode, perform an averaging process on the rest voltages of multiple battery clusters to obtain an average cluster voltage; compare the rest voltages of multiple battery clusters with the average cluster voltage respectively to determine target battery clusters with rest voltages less than the average cluster voltage; connect multiple battery clusters in pairs through an equalization loop, and perform equalization adjustment on the target battery clusters based on a pre-set equalization strategy.

[0075] In some embodiments, the energy storage system equalization module is further configured to request a first voltage and a first current from the target battery clusters for the equalization loop; the equalization loop performs equalization adjustment on the target battery clusters through the first voltage and the first current.

[0076] In some embodiments, the energy storage system balancing module is further configured to connect the lowest battery cluster corresponding to the lowest voltage and the highest battery cluster corresponding to the highest voltage through a balancing circuit. The lowest battery cluster requests a second voltage and a second current from the balancing circuit. The balancing circuit performs balancing adjustment on the lowest battery cluster through the second voltage and the second current until the inter-cluster static voltage difference between the lowest battery cluster and the highest battery cluster meets a preset static voltage difference threshold, and then disconnects the balancing circuit.

[0077] In some embodiments, the energy storage system balancing module is further configured to re-determine the lowest voltage and the highest voltage among the static voltages of the multiple battery clusters respectively, so as to balance the energy storage system until the inter-cluster static voltage differences of all the clusters meet the static voltage difference threshold.

[0078] In some embodiments, the balancing circuit includes a DC-DC converter. DC-DC converters are connected between multiple battery clusters. When performing balancing adjustment, the corresponding DC-DC converter is connected based on a balancing strategy.

[0079] The device provided by the embodiments of the present invention has the same implementation principle and the same technical effects as those of the foregoing method embodiments. For the sake of brief description, for the parts not mentioned in the device embodiments, reference may be made to the corresponding contents in the foregoing method embodiments.

[0080] Embodiment 4

[0081] The embodiments of the present invention further provide an electronic device for running the above-mentioned balancing method of the energy storage system; refer to Figure 5 As shown in the structural schematic diagram of an electronic device, the electronic device includes a memory 400 and a processor 401. Among them, the memory 400 is used to store one or more computer instructions, and the one or more computer instructions are executed by the processor 401 to implement the above-mentioned balancing method of the energy storage system.

[0082] Furthermore, Figure 5 The electronic device shown further includes a bus 402 and a communication interface 403. The processor 401, the communication interface 403, and the memory 400 are connected through the bus 402.

[0083] Among them, the memory 400 may include high-speed random access memory (RAM), and may also include non-volatile memory, such as at least one disk memory. The communication connection between this system network element and at least one other network element is realized through at least one communication interface 403 (which can be wired or wireless), and the Internet, wide area network, local area network, metropolitan area network, etc. can be used. The bus 402 can be an ISA bus, a PCI bus, an EISA bus, etc. The bus can be divided into an address bus, a data bus, a control bus, etc. For the sake of convenience of representation, Figure 5 only a bidirectional arrow is used in Figure 5 , but it does not mean that there is only one bus or one type of bus.

[0084] The processor 401 may be an integrated circuit chip with signal processing capabilities. In the implementation process, each step of the above method can be completed by the integrated logic circuit in hardware or instructions in software form in the processor 401. The above-mentioned processor 401 may be a general-purpose processor, including a central processing unit (CPU), a network processor (NP), etc.; it may also be a digital signal processor (DSP), an application specific integrated circuit (ASIC), a field programmable gate array (FPGA) or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components. It can implement or execute the various methods, steps and logic block diagrams disclosed in the embodiments of the present invention. The general-purpose processor may be a microprocessor or the processor may also be any conventional processor, etc. The steps of the method disclosed in combination with the embodiments of the present invention can be directly embodied as being executed and completed by a hardware decoding processor, or by a combination of hardware and software modules in the decoding processor. The software module may be located in a mature storage medium in the art such as random access memory, flash memory, read-only memory, programmable read-only memory or electrically erasable programmable memory, register, etc. This storage medium is located in the memory 400, and the processor 401 reads the information in the memory 400 and combines its hardware to complete the steps of the method in the foregoing embodiments.

[0085] An embodiment of the present invention also provides a computer-readable storage medium storing computer-executable instructions, which, when called and executed by a processor, cause the processor to implement the above-mentioned energy storage system balancing method. For specific implementation, reference can be made to the method embodiment, which will not be elaborated here.

[0086] A computer program product for implementing the energy storage system balancing method provided by an embodiment of the present invention includes a computer-readable storage medium storing non-volatile program code executable by a processor. The instructions included in the program code can be used to execute the method described in the foregoing method embodiment. For specific implementation, reference can be made to the method embodiment, which will not be elaborated here.

[0087] Those skilled in the art can clearly understand that for the sake of convenience and brevity of description, the specific working processes of the above-described systems, devices, and units can refer to the corresponding processes in the foregoing method embodiments, which will not be elaborated here.

[0088] In several embodiments provided by the present invention, it should be understood that the disclosed systems, devices, and methods can be implemented in other ways. The device embodiments described above are merely illustrative. For example, the division of the units is only a logical function division, and there may be other division methods in actual implementation. For another example, multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the displayed or discussed couplings, direct couplings, or communication connections to each other can be through some communication interfaces. The indirect couplings or communication connections of the devices or units can be in electrical, mechanical, or other forms.

[0089] The units described as separate components may or may not be physically separated. The components displayed as units may or may not be physical units, that is, they can be located in one place or distributed to multiple network units. Some or all of the units can be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0090] In addition, in each embodiment of the present invention, the functional units can be integrated into one processing unit, or each unit can exist physically alone, or two or more units can be integrated into one unit.

[0091] When the above-mentioned functions are implemented in the form of software functional units and sold or used as independent products, they can be stored in a non-volatile computer-readable storage medium executable by a processor. Based on such an understanding, the technical solution of the present invention, in essence, or the part that contributes to the prior art, or a part of the technical solution, can be embodied in the form of a software product. The computer software product is stored in a storage medium and includes several instructions for causing a computer device (which may be a personal computer, a server, or a network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of the present invention. The foregoing storage medium includes: various media that can store program codes, such as USB flash drives, mobile hard disks, read-only memories (ROM, Read-Only Memory), random access memories (RAM, Random Access Memory), magnetic disks, or optical discs.

[0092] Finally, it should be noted that the above-mentioned embodiments are only specific embodiments of the present invention, which are used to illustrate the technical solutions of the present invention, rather than to limit them. The protection scope of the present invention is not limited thereto. Although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that: any person skilled in the art within the technical scope disclosed by the present invention can still modify the technical solutions described in the foregoing embodiments or can easily think of changes, or perform equivalent replacements on some of the technical features; and these modifications, changes, or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present invention, and should all be covered by the protection scope of the present invention. Therefore, the protection scope of the present invention should be subject to the protection scope of the claims.

Claims

1. An equalization method for an energy storage system, characterized in that, The energy storage system includes multiple battery clusters, and the method includes: Obtaining the open-circuit voltage of each of the multiple battery clusters and the standby time corresponding to the energy storage system; Performing a difference operation on the open-circuit voltages of each of the multiple battery clusters in pairs to determine the open-circuit voltage differences between multiple clusters; Determining the equalization mode of the energy storage system based on the open-circuit voltage differences between multiple clusters and the standby time; If the equalization mode is the equalization maintenance mode, determining the lowest voltage and the highest voltage among the open-circuit voltages of each of the multiple battery clusters; Connecting the lowest battery cluster corresponding to the lowest voltage and the highest battery cluster corresponding to the highest voltage through an equalization circuit, and performing equalization adjustment on the lowest battery cluster and the highest battery cluster based on a preset equalization strategy; in the equalization maintenance mode, repeatedly determining the highest voltage and the lowest voltage until all the open-circuit voltage differences between clusters meet the open-circuit voltage difference threshold; The open-circuit voltage is the voltage of the battery cluster when no charge-discharge operation is performed, and the standby time is the duration during which the energy storage system does not perform charge-discharge operations; The equalization mode includes: equalization maintenance mode, equalization operation mode, and equalization standby mode; the equalization operation mode is a mode performed under the condition that the standby time is insufficient but there is an equalization requirement; If the equalization mode is the equalization operation mode, performing an averaging process on the open-circuit voltages of each of the multiple battery clusters to obtain an average cluster voltage; Comparing the open-circuit voltages of each of the multiple battery clusters with the average cluster voltage respectively to determine the target battery clusters whose open-circuit voltages are less than the average cluster voltage; Connecting each of the multiple battery clusters in pairs through an equalization circuit, and performing equalization adjustment on the target battery clusters based on a preset equalization strategy; The determining the equalization mode of the energy storage system based on the open-circuit voltage differences between multiple clusters and the standby time includes: Comparing the open-circuit voltage differences between multiple clusters with a preset voltage difference threshold respectively; If there is an open-circuit voltage difference between clusters that meets the voltage difference threshold, comparing the standby time with a preset time threshold; If the standby time is greater than the preset time threshold, the equalization mode is the equalization maintenance mode; If the standby time is less than or equal to the time threshold, the equalization mode is the equalization operation mode; If there is no open-circuit voltage difference between clusters that meets the voltage difference threshold, the equalization mode is the equalization standby mode.

2. The method according to claim 1, wherein The performing equalization adjustment on the target battery clusters based on a preset equalization strategy includes: The target battery clusters request a first voltage and a first current from the equalization circuit; The equalization circuit performs equalization adjustment on the target battery clusters through the first voltage and the first current.

3. The method according to claim 1, characterized in that The connecting the lowest battery cluster corresponding to the lowest voltage and the highest battery cluster corresponding to the highest voltage through an equalization circuit, and performing equalization adjustment on the lowest battery cluster and the highest battery cluster based on a preset equalization strategy includes: Connecting the lowest battery cluster corresponding to the lowest voltage and the highest battery cluster corresponding to the highest voltage through an equalization circuit, and the lowest battery cluster requests a second voltage and a second current from the equalization circuit; The balancing circuit adjusts the lowest battery cluster through the second voltage and the second current until the inter-cluster static pressure difference between the lowest battery cluster and the highest battery cluster meets a preset static pressure difference threshold, and then disconnects the balancing circuit.

4. The method according to claim 3, characterized in that, After disconnecting the balancing circuit, the method further includes: Determining again the lowest voltage and the highest voltage among the static voltages of the multiple battery clusters respectively to balance the energy storage system until the inter-cluster static pressure differences all meet the static pressure difference threshold.

5. The method according to claim 1, wherein The balancing circuit includes a DC-DC converter, and the DC-DC converter is connected between multiple battery clusters. When performing balancing adjustment, the corresponding DC-DC converter is connected based on the balancing strategy.

6. An equalization device for an energy storage system, characterized in that, For implementing the balancing method of the energy storage system according to any one of claims 1 to 5, the energy storage system includes multiple battery clusters, and the device includes: An acquisition module, configured to acquire the static voltages of the multiple battery clusters respectively and the standby time corresponding to the energy storage system; An inter-cluster static pressure difference determination module, configured to perform a difference operation on the static voltages of the multiple battery clusters pairwise to determine multiple inter-cluster static pressure differences; An equalization mode determination module, configured to determine the equalization mode of the energy storage system based on the multiple inter-cluster static pressure differences and the standby time; A voltage determination module, configured to determine the lowest voltage and the highest voltage among the static voltages of the multiple battery clusters respectively if the equalization mode is an equalization maintenance mode; An energy storage system balancing module, configured to connect the lowest battery cluster corresponding to the lowest voltage and the highest battery cluster corresponding to the highest voltage through a balancing circuit based on a preset balancing strategy to balance the energy storage system.

7. An electronic device, characterized in that, It includes a processor and a memory. The memory stores computer-executable instructions that can be executed by the processor, and the processor executes the computer-executable instructions to implement the balancing method of the energy storage system according to any one of claims 1 to 5.

8. A computer-readable storage medium, characterized in that The computer-readable storage medium stores computer-executable instructions. When the computer-executable instructions are called and executed by the processor, the computer-executable instructions cause the processor to implement the balancing method of the energy storage system according to any one of claims 1 to 5.

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