Balancing method, terminal equipment, energy storage system and computer readable storage medium

Abstract

The invention is suitable for the technical field of energy storage, and provides an equalization method, terminal equipment, a storage system and a computer readable storage medium, and the method comprises the steps: obtaining a target parameter value of each energy storage sub-module; determining a homogenization degree deviation value of the energy storage system according to the target parameter value of each energy storage sub-module; if the uniformization degree deviation is greater than or equal to the starting threshold value, determining a target switching sub-module of the current control period according to a first selection strategy; if the uniformization degree deviation is smaller than the starting threshold value, determining a target switching sub-module of the current control period according to a second selection strategy; switching operation is executed on the target switching sub-module, the target switching sub-module is determined by adopting a strategy determined based on target parameter balance under the condition that the balance state is poor, and the target switching sub-module is determined by adopting a strategy determined based on switching times under the condition that the balance state is good; and the average switching frequency and the switching loss of the energy storage sub-module can be reduced as much as possible.

Description

Technical Field

[0001] The present application belongs to the field of energy storage technology, and in particular, relates to an energy storage submodule balancing method, a terminal device, an energy storage system, and a computer-readable storage medium. Background Art

[0002] Compared with traditional energy storage systems, high-voltage and large-capacity energy storage systems have stronger regulation capabilities for flexible DC transmission systems, are more suitable for the application scenarios of offshore wind power output via flexible DC, have lower system network losses, higher economic benefits, and higher operational reliability. Therefore, high-voltage and large-capacity energy storage systems have important research significance for new power systems based on new energy.

[0003] At present, high-voltage and large-capacitance energy storage systems generate high switching losses when balancing energy storage sub-modules, which affects the service life of power devices and systems. Summary of the invention

[0004] In view of the above problems, the present application provides a balancing method, a terminal device, an energy storage system and a computer-readable storage medium, which can minimize the average switching times and switching losses of the energy storage submodules while achieving balancing of the energy storage submodules, thereby extending the service life of the energy storage system.

[0005] In a first aspect, an embodiment of the present application provides a balancing method, including:

[0006] Obtain target parameter values ​​for each energy storage submodule;

[0007] Determining a homogenization degree deviation value of the energy storage system according to target parameter values ​​of each of the energy storage submodules;

[0008] If the homogenization degree deviation is greater than or equal to the start threshold, determining the target switching submodule of the current control cycle according to a first selection strategy; the first selection strategy is set based on the equilibrium state of the target parameter;

[0009] If the homogenization degree deviation is less than the start threshold, the target switching submodule of the current control cycle is determined according to a second selection strategy; the second selection strategy is set based on the average switching times of the energy storage submodule;

[0010] Perform switching operation on the target switching submodule.

[0011] In the embodiment of the present application, by determining the equilibrium state of the energy storage system, when the equilibrium state is poor, a strategy based on target parameter equilibrium is adopted to determine the energy storage submodule to be put into or cut out, and when the equilibrium state is good, a strategy based on the number of switching times is adopted to determine the energy storage submodule to be put into or cut out. This can minimize the average number of switching times and switching losses of the energy storage submodules and extend the service life of the energy storage system while achieving equilibrium of the energy storage submodules.

[0012] In some possible implementations of the first aspect, the target switching submodule includes a first target input submodule, a second input submodule, and a second switch-out submodule, and if the homogenization degree deviation is greater than or equal to a start threshold, determining the target switching submodule of the current control cycle according to a first selection strategy includes:

[0013] Sorting the target parameters of all the energy storage submodules in descending order according to their priorities to obtain a sorting result;

[0014] Determine the first a energy storage submodules in the sorting result as the first target input submodule; wherein a is a positive integer;

[0015] The second target input submodule or the second target cut-out submodule is determined according to the input quantity of the current control cycle and the input quantity of the previous control cycle.

[0016] In the embodiment of the present application, when the balanced state of the energy storage system is poor, the first target input submodule can be determined according to the priority sorting result, so that the balanced state of the energy storage system can be quickly adjusted.

[0017] In some possible implementations of the first aspect, determining the second target input submodule or the second target cutout submodule according to the input quantity of the current control cycle and the input quantity of the previous control cycle includes:

[0018] If the input quantity of the current control cycle is equal to the input quantity of the previous control cycle, it is determined that the second target input submodule and the second target cut-out submodule do not exist;

[0019] If the input quantity of the current control cycle is less than the input quantity of the previous control cycle, the second target cut-out submodule is determined by cutting out the input submodules in turn;

[0020] If the number of inputs in the current control cycle is greater than the number of inputs in the previous control cycle, the first |Δn| cut-out energy storage submodules in the sorting result are determined as the second target input submodules; wherein Δn is the difference between the number of inputs in the current control cycle and the number of inputs in the previous control cycle.

[0021] In an embodiment of the present application, when the energy storage sub-module needs to be cut out in the current control cycle, the target sub-module to be cut out can be determined based on the method of switching out in turns, which can effectively reduce the average switching frequency of the energy storage sub-module, reduce the device loss of the energy storage sub-module, and extend the service life of the energy storage sub-module and the energy storage system.

[0022] In some possible implementations of the first aspect, after determining the second target input submodule or the second target cutout submodule according to the input quantity of the current control cycle and the input quantity of the previous control cycle, the method further includes:

[0023] Re-obtaining target parameter values ​​of each energy storage submodule, and recalculating the homogenization degree deviation;

[0024] If the recalculated homogenization degree deviation is less than the return threshold, it is determined that the current control cycle is ended, otherwise the target step and the subsequent steps of the target step are repeated until the recalculated homogenization degree deviation is less than the return threshold; the target step is to sort the target parameters of all the energy storage sub-modules in descending order according to their priorities to obtain a sorting result.

[0025] In some possible implementations of the first aspect, the target switching submodule includes a first target switching submodule, and if the homogenization degree deviation is greater than or equal to a start threshold, determining the target switching submodule of the current control cycle according to a first selection strategy includes:

[0026] Determine the last b energy storage submodules in the sorting result as the first target cut-out submodules, where b is a positive integer.

[0027] In the embodiment of the present application, when the balanced state of the energy storage system is poor, the first target submodule to be cut out can be determined through the priority sorting result, so that the balanced state of the energy storage system can be quickly adjusted.

[0028] In some possible implementations of the first aspect, the target switching submodule includes a third target input submodule and a third target switch-out submodule, and if the homogenization degree deviation is less than the start threshold, determining the target switching submodule of the current control cycle according to the second selection strategy includes:

[0029] Determine the submodule change amount according to the input quantity of the current control cycle and the input quantity of the previous control cycle;

[0030] A third target input submodule or a third target cutout submodule is determined according to the submodule change amount.

[0031] When the energy storage system is in a well-balanced state, all energy storage submodules can be switched on and off in turn, thereby reducing the average switching times of the energy storage submodules and the average switching frequency of the submodules.

[0032] In some possible implementations of the first aspect, determining a third target input submodule or a third target cutout submodule according to the submodule change amount includes:

[0033] If the submodule change amount is 0, it is determined that the third target input submodule and the third target cut-out submodule do not exist;

[0034] If the submodule change amount is less than 0, the third target submodule to be switched out is determined in a rotating manner according to the sorting result of the previous control cycle;

[0035] If the submodule change is greater than 0, the sorting result of the previous control cycle is updated according to the submodule change to obtain an updated sorting result; and the first n energy storage submodules are determined as the third target investment submodules according to the updated sorting result; wherein n is the number of submodules required to be invested in the current control cycle.

[0036] In the embodiment of the present application, when the energy storage system is in a better balanced state, all energy storage sub-modules can be switched on and off in turn, thereby reducing the average switching times of the energy storage sub-modules, reducing the average switching frequency of the sub-modules, and reducing the number of sorting times, thereby reducing the demand for resources of the energy storage valve controller's hardware and software.

[0037] In some possible implementations of the first aspect, the balancing method further includes:

[0038] Initialize the sorting of all energy storage submodules to obtain the initialization sorting result.

[0039] In an embodiment of the present application, the energy storage submodules are initialized at the beginning to obtain the initialization sorting results of each energy storage submodule. When the uniformity deviation value of the energy storage system is small, the initialization sorting results obtained by initialization can be used to switch the energy storage submodules in the energy storage system in turn, which can effectively reduce the number of sorting times of the controller and can effectively reduce the demand for software and hardware resources of the energy storage submodules. In a second aspect, an embodiment of the present application provides a terminal device, the terminal device includes a processor, a memory, and a computer program stored in the memory and executable on the processor, and when the processor executes the computer program, it implements the balancing method described in the first aspect or any optional method of the first aspect.

[0040] In a third aspect, an embodiment of the present application provides an energy storage system, which includes a plurality of energy storage sub-modules and a terminal device as described in the second aspect.

[0041] In a fourth aspect, an embodiment of the present application provides a computer-readable storage medium, wherein the computer-readable storage medium stores a computer program, and when the computer program is executed by a processor, the balancing method as described in the first aspect or any optional method of the first aspect is implemented.

[0042] The above description is only an overview of the technical solution of the present application. In order to more clearly understand the technical means of the present application, it can be implemented in accordance with the contents of the specification. In order to make the above and other purposes, features and advantages of the present application more obvious and easy to understand, the specific implementation methods of the present application are listed below. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] Various other advantages and benefits will become apparent to those of ordinary skill in the art by reading the detailed description of the preferred embodiments below. The accompanying drawings are only for the purpose of illustrating the preferred embodiments and are not to be considered as limiting the present application. Moreover, the same reference numerals are used throughout the drawings to represent the same components. In the drawings:

[0044] Figure 1 A schematic diagram of the architecture of the MMC type energy storage system provided in the embodiment of the present application;

[0045] Figure 2 A schematic diagram of the architecture of a cascade energy storage system provided in an embodiment of the present application;

[0046] Figure 3 A schematic diagram of the architecture of a DC direct-mounted energy storage system provided in an embodiment of the present application;

[0047] Figure 4 A schematic diagram of the structure of a half-bridge power module of an energy storage system provided in an embodiment of the present application;

[0048] Figure 5 A schematic diagram of the structure of a full-bridge power module of an energy storage system provided in an embodiment of the present application;

[0049] Figure 6 A schematic diagram of the implementation flow of the balancing method provided in the embodiment of the present application;

[0050] Figure 7 A schematic diagram of the implementation flow of S13 in the balancing method provided in an embodiment of the present application;

[0051] Figure 8 A schematic diagram of the implementation flow of S133 in the balancing method provided in other embodiments of the present application;

[0052] Fig. 9A schematic diagram of the implementation flow of S13 in the balancing method provided in other embodiments of the present application;

[0053] Fig.10 A schematic diagram of the implementation flow of S14 in the equalization method provided in some embodiments of the present application;

[0054] Fig.11 A schematic diagram of the implementation flow of S142 in the balancing method provided in other embodiments of the present application;

[0055] Fig.12 A schematic diagram of the structure of an equalizing device provided in some embodiments of the present application;

[0056] Fig.13 A schematic diagram of the structure of a terminal device provided for some embodiments of the present application. DETAILED DESCRIPTION

[0057] The following embodiments of the technical solution of the present application are described in detail in conjunction with the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solution of the present application, and are therefore only used as examples, and cannot be used to limit the scope of protection of the present application.

[0058] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by technicians in the technical field to which this application belongs; the terms used herein are only for the purpose of describing specific embodiments and are not intended to limit this application; the terms "including" and "having" in the specification and claims of this application and the above-mentioned figure descriptions and any variations thereof are intended to cover non-exclusive inclusions.

[0059] In the description of the embodiments of the present application, the technical terms "first", "second", etc. are only used to distinguish different objects, and cannot be understood as indicating or implying relative importance or implicitly indicating the number, specific order or primary and secondary relationship of the indicated technical features. In the description of the embodiments of the present application, the meaning of "multiple" is more than two, unless otherwise clearly and specifically defined.

[0060] Reference to "embodiments" herein means that a particular feature, structure, or characteristic described in conjunction with the embodiments may be included in at least one embodiment of the present application. The appearance of the phrase in various locations in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0061] In the description of the embodiments of the present application, the term "and / or" is only a description of the association relationship of the associated objects, indicating that there may be three relationships. For example, A and / or B can represent: A exists alone, A and B exist at the same time, and B exists alone. In addition, the character " / " in this article generally indicates that the associated objects before and after are in an "or" relationship.

[0062] In the description of the embodiments of the present application, the term "multiple" refers to more than two (including two). Similarly, "multiple groups" refers to more than two groups (including two groups), and "multiple pieces" refers to more than two pieces (including two pieces).

[0063] In the description of the embodiments of the present application, the technical terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, which are only for the convenience of describing the embodiments of the present application and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the embodiments of the present application.

[0064] In the description of the embodiments of the present application, unless otherwise clearly specified and limited, technical terms such as "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, and it can be the internal connection of two elements or the interaction relationship between two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the embodiments of the present application can be understood according to the specific circumstances.

[0065] Energy storage refers to the process of storing energy through a medium or device and releasing it when needed. Compared with traditional energy storage systems, high-voltage and large-capacity energy storage systems have stronger regulation capabilities for flexible DC transmission systems, are more suitable for application scenarios of offshore wind power output via flexible DC, have lower system network losses, higher economic benefits, and higher operational reliability.

[0066] High-voltage, large-capacity energy storage systems include, but are not limited to, modular multilevel converter (MMC) energy storage systems, cascade energy storage systems, and DC direct-mounted energy storage systems.

[0067] For example, see Figures 1 to 3 , which are schematic architecture diagrams of MMC energy storage system, cascade energy storage system and DC direct-mounted energy storage system respectively.

[0068] like Figures 1 to 3 It can be seen that the above-mentioned high-voltage and large-capacity energy storage system 1 may include a plurality of energy storage submodules SM, for example Figure 1 The MMC type energy storage system 11 includes 6*N energy storage submodules SM ( Figure 1 In the figure, they are represented as 6 groups SM1 to SMN), and Figure 2 The cascade energy storage system 12 includes 3*N energy storage submodules SM ( Figure 2 In the figure, they are represented as 3 groups SM1~SMN), and Figure 3 The DC direct-mounted energy storage system 13 includes N energy storage submodules SM ( Figure 3 are represented as SM1~SMN respectively).

[0069] The energy storage submodule SM includes a power module 20 and a battery module 30 .

[0070] The power module 20 may be implemented as follows: Figure 4 The half-bridge power module shown in FIG. 1 , the corresponding energy storage submodule SM is a half-bridge energy storage submodule; the power module 20 may also be a half-bridge power storage submodule. Figure 5 The full-bridge power module shown in FIG. 1 , then the corresponding energy storage module SM is a full-bridge energy storage submodule.

[0071] The battery module 30 may be a single-branch series-connected battery module or a multi-branch series-parallel battery module.

[0072] Wherein, N is an integer greater than or equal to 1.

[0073] In order to further improve the system power and capacity of high-voltage and large-capacity energy storage systems, this can be achieved by adding cascaded energy storage sub-modules. How to achieve balance between multiple energy storage sub-modules is an important issue in the application of energy storage systems.

[0074] In energy storage systems, the balance of energy storage submodules is usually achieved through phase-shifted pulse width modulation (PSPWM). However, in the case of cascading multiple energy storage submodules in the energy storage system, the control algorithm design of the PSPWM modulation strategy becomes more complicated and will also cause greater losses. At present, the balance of multiple cascaded energy storage submodules is achieved by the nearest level modulation (NLM) modulation strategy. The NLM modulation strategy can reduce the switching frequency and achieve dynamic balance of multiple energy storage submodules.

[0075] However, since the modulation process of the high-voltage and large-capacity energy storage system will generate high-frequency modulation signals (such as modulation signals with a frequency of more than 100Hz) to the energy storage system or a single energy storage submodule, it will cause frequent switching of the energy storage submodule, affecting the service life of the power device and the system. That is, the above-mentioned balancing methods cannot be directly applied to high-voltage and large-capacity energy storage systems. It is now urgent to provide a balancing method that can be applied to high-voltage and large-capacity energy storage systems, can achieve dynamic balancing performance of submodules of high-voltage and large-capacity energy storage systems, and can reduce the average switching frequency of submodules.

[0076] Based on the above considerations, in order to solve the problem that high switching losses will be generated when balancing the energy storage sub-modules in a high-voltage and large-capacitance energy storage system, thereby affecting the service life of power devices and the system, an embodiment of the present application proposes a balancing method, which determines the balanced state of the energy storage system. When the balanced state is poor, a strategy based on target parameter balancing is used to determine the energy storage sub-module to be put into or cut out. When the balanced state is good, a strategy based on the number of switching times is used to determine the energy storage sub-module to be put into or cut out. This method can minimize the average number of switching times and switching losses of the energy storage sub-modules while achieving balancing of the energy storage sub-modules, thereby extending the service life of the energy storage system.

[0077] The balancing method provided in the embodiment of the present application can be applied to the above energy storage system, and specifically the balancing method provided in the embodiment of the present application can be executed by the energy storage valve controller of the energy storage system. The above energy storage system 1 includes at least two energy storage submodules SM, which are connected in series.

[0078] See also Figure 6 , Figure 6 The following is a schematic implementation flow chart of an equalization method provided in some embodiments of the present application. Figure 6 As shown, the above-mentioned equalization method may include S11-S15, which are described in detail as follows:

[0079] S11: Obtain target parameter values ​​of each energy storage submodule.

[0080] In the embodiment of the present application, the target parameter refers to a parameter that can reflect the working state of the energy storage submodule, and is a parameter considered when the energy storage system performs balancing, that is, the energy storage valve controller of the energy storage system performs system balancing based on the target parameter. The above target parameter value refers to the value of the target parameter at the current moment.

[0081] In a specific application, the above target parameters may include but are not limited to the state of charge (SOC) of the battery module of the energy storage submodule, the normalized parameters of the energy storage submodule, and the capacitor voltage of the energy storage submodule.

[0082] It should be noted that the normalized parameters of the energy storage submodule mentioned in the embodiment of the present application refer to parameters that can reflect the normalization degree of the energy storage submodule. The above normalized parameters can be determined by parameters such as the state of charge of the battery module of the energy storage submodule, the state of health (SOH) of the energy storage submodule, and the maximum power (SOP) of the battery module of the energy storage submodule during charging and discharging.

[0083] In specific applications, when the energy storage system is balanced and adjusted, the parameter to be selected as the target parameter can be determined according to the actual application scenario. For example, for traditional flexible direct current transmission scenarios, the capacitor voltage of the energy storage submodule can be selected as the target parameter; for application scenarios with a greater impact on the battery status, the SOC of the battery module of the energy storage submodule can be selected as the target parameter or the normalized parameter of the energy storage submodule can be selected as the target parameter.

[0084] In a specific application, the energy storage valve controller can obtain the target parameter value of each energy storage submodule at the current moment in real time through a device such as a battery management system (BMS) or a battery management unit, for example, obtaining the normalized parameter value of each energy storage submodule at the current moment.

[0085] In a specific application, when the energy storage valve controller of the energy storage system needs to switch on or off the energy storage submodule, the target parameter value at the current moment can be obtained through the BMS, for example, the SOC value of the battery of each energy storage submodule can be obtained through the BMS.

[0086] S12: Determine a uniformity deviation value of the energy storage system according to target parameter values ​​of each of the energy storage submodules.

[0087] The above-mentioned uniformity deviation value of the energy storage system is used to characterize the uniformity of the energy storage system at the current moment. If the uniformity deviation value is large, it means that the equilibrium state of the energy storage system at the current moment is poor, and if the uniformity deviation value is small, it means that the equilibrium state of the energy storage system at the current moment is good.

[0088] In an embodiment of the present application, the above-mentioned determination of the homogenization degree deviation value of the energy storage system according to the target parameter value of each of the energy storage submodules may include the following steps:

[0089] Obtaining the maximum and minimum values ​​of the target parameter values ​​of each of the energy storage submodules;

[0090] The difference between the maximum value and the minimum value is calculated, and the difference is determined as the normalization degree deviation value.

[0091] Exemplarily, assume that the energy storage system includes 6 energy storage sub-modules. Taking the target parameter value as the SOC value as an example, the target parameter values include SOC1 of the first energy storage sub-module, SOC2 of the second energy storage sub-module, the target parameter value SOC3 of the third energy storage sub-module, the target parameter value SOC4 of the third energy storage sub-module, SOC5 of the fifth energy storage sub-module, and SOC6 of the sixth energy storage sub-module, where SOC1 < SOC2 < SOC3 < SOC4 < SOC5 < SOC6; then the maximum SOC can be determined as SOC6, and the minimum SOC as SOC1. Therefore, the deviation value ΔS of the homogenization degree max = SOC6 - SOC1.

[0092] In some embodiments of the present application, the above deviation value of the homogenization degree can also be calculated in other ways using the target parameter values of each energy storage sub-module. For example, it can also be the average value of the differences of each energy storage sub-module, etc.

[0093] S13: If the deviation of the homogenization degree is greater than or equal to the starting threshold, determine the target switching sub-module of the current control period according to the first selection strategy.

[0094] In specific applications, the above starting threshold is a parameter set according to the actual equalization requirements. Assume that the target parameter of the energy storage system is a normalized parameter, and assume that the equalization requirement of the energy storage system is to ensure that the homogenization degree is less than 10%. Then the above starting threshold can be set to 10%. If the deviation of the homogenization degree of the energy storage system is greater than or equal to this starting threshold, it means that the equalization state of the energy storage system is poor; otherwise, it indicates that the equalization state of the energy storage system is good.

[0095] In the embodiments of the present application, the above first selection strategy is based on the equalization state of the target parameter, and the first selection strategy is a selection strategy for the energy storage sub-module that gives priority to system equalization. That is, the target switching sub-module determined by the first selection strategy is the energy storage sub-module that can achieve system equalization faster.

[0096] S14: If the deviation of the homogenization degree is less than the starting threshold, determine the target switching sub-module of the current control period according to the second selection strategy.

[0097] In specific applications, the second selection strategy is a selection strategy for the energy storage sub-module based on the average switching times of the energy storage sub-module. That is, the target switching sub-module determined by the second selection strategy can reduce the average switching times of the energy storage sub-module.

[0098] S15: Perform a switching operation on the target switching sub-module.

[0099] In the embodiments of the present application, the above target switching sub-module includes a target input sub-module and a target cut-out sub-module.

[0100] In the embodiment of the present application, the above-mentioned performing a switching operation on the target switching submodule refers to: performing a switching operation on the target switching-in submodule, or performing a switching-out operation on the target switching-out submodule.

[0101] In a specific application, if the energy storage valve controller determines that M energy storage sub-modules need to be put into operation in the current control cycle, the target input sub-module can be determined through the first selection strategy and the second selection strategy, and the target input sub-module can be controlled to switch to the input state; if the energy storage valve controller determines that M energy storage sub-modules need to be cut out in the current control cycle, the target cut-out sub-module can be determined through the first selection strategy and the second selection strategy, and the target cut-out sub-module can be controlled to switch to the cut-out state.

[0102] In a specific application, the energy storage valve controller may adopt a modulation strategy when modulating the target input submodule / target cut-out submodule.

[0103] Specifically, the above-mentioned modulation strategies include but are not limited to specific harmonic elimination step wave (selective harmonic elimination pulse width modulation, SHESM) modulation strategy, nearest level approximation modulation strategy, space vector control strategy, carrier disposition pulse width modulation (carrier disposition pulse width modulation) modulation strategy, carrier phase-shift PWM modulation (carrier phase-shift pulse width modulation) modulation strategy, etc.

[0104] It can be seen from the above that the balancing method provided in the embodiment of the present application can determine the balanced state of the energy storage system. When the balanced state is poor, a strategy based on target parameter balance is adopted to determine the energy storage sub-module to be put into or cut out. When the balanced state is good, a strategy based on the number of switching times is adopted to determine the energy storage sub-module to be put into or cut out. This can minimize the average number of switching times and switching losses of the energy storage sub-modules and extend the service life of the energy storage system while achieving the balance of the energy storage sub-modules.

[0105] See also Figure 7 In one embodiment of the present application, the above S13 may include the following steps:

[0106] S131: Sorting the target parameters of all the energy storage submodules in descending order according to their priorities to obtain a sorting result.

[0107] In an embodiment of the present application, the priority of the energy storage submodule can be specifically determined according to the charge and discharge state of the energy storage system and the type of target parameter. Exemplarily, assuming that the charge and discharge state of the energy storage system is the charging state, when the target parameter is a normalized parameter, the higher the normalized parameter, the higher the priority of the energy storage submodule; when the target parameter is SOC, the lower the SOC, the higher the priority of the energy storage submodule; when the target parameter is the capacitor voltage of the energy storage submodule, the lower the capacitor voltage, the higher the priority of the energy storage submodule. Assuming that the charge and discharge state of the energy storage system is the discharge state, when the target parameter is a normalized parameter, the higher the normalized parameter, the higher the priority of the energy storage submodule; when the target parameter is SOC, the higher the SOC, the higher the priority of the energy storage submodule; when the target parameter is the capacitor voltage, the higher the capacitor voltage, the higher the priority of the energy storage submodule.

[0108] After determining the priority of each energy storage submodule, the priorities of the energy storage submodules are sorted in descending order, and the sorting result of the energy storage submodules in the current control cycle can be obtained.

[0109] S132: Determine the first a energy storage submodules in the sorting result as the first target input submodule.

[0110] In the embodiment of the present application, since the difference in the degree of homogenization of the energy storage system is greater than or equal to the start-up threshold, it indicates that the equilibrium state of the energy storage system is poor, and therefore, it is necessary to give priority to adjusting the equilibrium state of the energy storage system. After determining the above sorting results, the energy storage submodules at the front of the sorting are put into the energy storage system, which can adjust the equilibrium state of the energy storage system more quickly. Therefore, the first a energy storage submodules in the sorting results are determined as the first target input submodules.

[0111] After the energy storage valve controller determines the a first target input submodule, it will continue to input the a first target input submodule into the energy storage system to adjust the equilibrium state of the energy storage system so that the equilibrium state of the energy storage system can reach the equilibrium requirement as soon as possible.

[0112] In specific applications, the value of a can be calculated based on the total number of energy storage submodules N, the number of input modules in the current control cycle n, and the number of modules that need to be switched in turn n. tr Sure.

[0113] Specifically, 0<a<min{Nn tr ,n}, where n tr =f sys / f set , f sys is the system modulation required frequency, f set is the device target control frequency, and min{} is the minimum function.

[0114] S133: Determine a second target input submodule or a second target cut-out submodule according to the input quantity of the current control cycle and the input quantity of the previous control cycle.

[0115] In a specific application, the input quantity n of the current control cycle can be determined by the valve controller of the energy storage system according to a modulation strategy.

[0116] In a specific application, the input quantity of the current control cycle can be determined according to the reference voltage of the current cycle and the average capacitor voltage of each energy storage submodule.

[0117] Specifically, the input quantity n of the current control cycle can be expressed as: n=round(U ref / U c ), where U ref is the reference voltage of the current cycle, U c is the average capacitor voltage of each energy storage submodule. round() is the rounding function.

[0118] In a specific application, the reference voltage of the current cycle can be obtained by an inner and outer loop proportional-integral regulation algorithm.

[0119] In a specific application, the average capacitor voltage of each energy storage submodule can be obtained by acquiring the capacitor voltage of each energy storage submodule in the energy storage system and then calculating it through an average value function.

[0120] See also Figure 8 In one embodiment of the present application, the above S133 may specifically include the following steps:

[0121] S1331: If the input quantity of the current control cycle is equal to the input quantity of the previous control cycle, it is determined that the second target input submodule and the second target cut-out submodule do not exist.

[0122] In a specific application, since the number of inputs in the current control cycle is equal to the number of inputs in the previous control cycle, it means that there is no need to increase or decrease the energy storage sub-modules running in the energy storage system at this time. Therefore, there is no need to input or cut out the sub-modules. Therefore, it can be determined that there is no second target input sub-module and second target cut-out sub-module.

[0123] S1332: If the input quantity of the current control cycle is less than the input quantity of the previous control cycle, determine the second target sub-module to be cut out by switching out the input sub-modules in turn.

[0124] In a specific application, the number of inputs in the current control cycle is less than the number of inputs in the previous control cycle, indicating that the current control cycle needs to cut out |Δn| energy storage submodules from the energy storage submodules that have been put into operation. Among them, Δn is the submodule change, Δn=n k -n k-1 ; where n k is the input quantity of the current control cycle, n k-1 is the input quantity of the previous control period.

[0125] In the embodiment of the present application, determining the second target submodule to be cut out by switching out the already put into operation submodules in turn means that the already put into operation energy storage submodules in the energy storage system are determined in turn as the second target submodule to be cut out.

[0126] Exemplarily, assume that the energy storage system includes 6 energy storage sub-modules, among which the energy storage sub-modules that have been put into operation include {the first energy storage sub-module SM1, the second energy storage sub-module SM2, the third energy storage sub-module SM3, and the fourth energy storage sub-module SM4}. If Δn is determined to be -1, it means that an energy storage sub-module needs to be cut out in the current control cycle. Assuming that the fourth energy storage sub-module SM4 has been cut out in the last two rounds, the fourth energy storage sub-module SM4 is put into operation in the last control cycle (that is, the fourth energy storage sub-module has been turned once), the third energy storage sub-module SM3 will be determined as the second target cut-out sub-module.

[0127] That is, in the embodiment of the present application, the energy storage sub-modules are switched out in turn, and there is no need for the controller to sort them. This reduces the consumption of computing resources. By controlling the switching out of the energy storage sub-modules in turn, the frequent switching out of a single energy storage sub-module can be reduced, thereby reducing the average switching frequency of the energy storage sub-modules.

[0128] S1333: If the number of input submodules in the current control cycle is greater than the number of input submodules in the previous control cycle, the first |Δn| switched-out energy storage submodules in the sorting result are determined as second target input submodules.

[0129] In the embodiment of the present application, the number of investments in the current control cycle is greater than the number of investments in the previous control cycle, indicating that |Δn| energy storage sub-modules need to be invested in the energy storage system in the current control cycle.

[0130] In a specific application, when it is determined that |Δn| energy storage submodules need to be put into use, the first |Δn| removed energy storage submodules are determined as second target submodules to be put into use according to the priority sorting results from the removed energy storage submodules.

[0131] S134: reacquire the target parameter value of each energy storage submodule, and recalculate the homogenization degree deviation.

[0132] In a specific application, after the above steps are completed, the energy storage valve controller can perform switching control according to the above first target input submodule, the above first target cut-out submodule, the above second target input submodule, and the above second target input submodule. The equilibrium state of the energy storage system will change accordingly. In order to determine whether it is possible to exit the operation of always inputting the first a energy storage submodules, it is necessary to redetermine the equilibrium state of the energy storage system. Therefore, the target parameter values ​​of each energy storage submodule can be reacquired, and the homogenization degree deviation value can be recalculated.

[0133] S135: If the recalculated average degree deviation is smaller than the return threshold, it is determined that the current control cycle is ended; otherwise, S131 to S134 are re-executed until the recalculated average degree deviation is smaller than the return threshold.

[0134] In the embodiment of the present application, the above return threshold can be set according to the sampling error of the energy storage system. For example, if the sampling error of the energy storage system is ±3%, the return threshold can be set to 6%.

[0135] In the embodiment of the present application, the return threshold is smaller than the start threshold.

[0136] Different from the previous embodiment, please refer to Fig. 9 In the embodiment of the present application, the above S13 may further include the following steps:

[0137] S136: Determine the last b energy storage submodules in the sorting result as the first target cut-out submodules.

[0138] In the embodiment of the present application, after determining the above-mentioned sorting result, the energy storage submodules at the back of the sorting are cut out from the energy storage system, which can also adjust the equilibrium state of the energy storage system more quickly. Therefore, the last b energy storage submodules in the sorting result are determined as the first target cut-out submodules.

[0139] After the energy storage valve controller determines the b first target cut-out submodules, it will continue to cut out the b first target cut-out submodules from the energy storage system to adjust the equilibrium state of the energy storage system so that the equilibrium state of the energy storage system can reach the equilibrium requirement as soon as possible.

[0140] In specific applications, the value of b can be calculated based on the total number of energy storage submodules N, the number of input modules in the current control cycle n, and the number of modules that need to be switched in turn n. tr Sure.

[0141] Specifically, 0<b<min{Nn tr ,Nn}, where n tr =f sys / f set , f sysis the system modulation required frequency, f set is the device target control frequency, and min{} is the minimum function.

[0142] It can be seen from the above that in the embodiment of the present application, when the balanced state of the energy storage system is poor, the first target input submodule or the first target cut-out submodule can be determined through the priority sorting result, so that the balanced state of the energy storage system can be quickly adjusted, and when the energy storage submodule needs to be cut out in the current control cycle, the target cut-out submodule can be determined based on the rotation cut-out method, which can effectively reduce the average switching frequency of the energy storage submodule, reduce the device loss of the energy storage submodule, and extend the service life of the energy storage submodule and the energy storage system.

[0143] See also Fig.10 In one embodiment of the present application, the above S14 may include the following steps:

[0144] S141: Determine the submodule change amount according to the input quantity of the current control cycle and the input quantity of the previous control cycle.

[0145] Where Δn=n k -n k-1 ; Δn is the submodule change, n k is the input quantity of the current control cycle, n k-1 is the input quantity of the previous control period.

[0146] S142: Determine a third target input submodule or a third target cutout submodule according to the submodule variation.

[0147] Please refer to 11. In one embodiment of the present application, the above S142 may include the following steps:

[0148] S1421: If the submodule change amount is 0, it is determined that the third target input submodule and the third target cut-out submodule do not exist.

[0149] S1422: If the submodule change amount is less than 0, determine the third target submodule to be switched out in a rotating manner according to the sorting result of the previous control cycle.

[0150] In a specific application, since the submodule change is less than 0, it means that the number of inputs in the current control cycle is less than that in the previous control cycle, that is, the current control cycle needs to cut out |Δn| energy storage submodules from the energy storage submodules that have been put into operation.

[0151] In an embodiment of the present application, utilizing the sorting result of the previous control cycle to determine the third target sub-module to be cut out in a rotational manner means that the sequence number of the energy storage sub-module is controlled unchanged through the sorting result of the previous control cycle, and the energy storage sub-modules already put into use in the energy storage system are determined as the third target sub-module to be cut out in turn.

[0152] Exemplarily, assuming that the sorting result of the previous control cycle is {the first energy storage submodule SM1, the second energy storage submodule SM2, the third energy storage submodule SM3, the fourth energy storage submodule SM4}, and it is necessary to cut out an energy storage submodule at this time, then the fourth energy storage submodule SM4 can be determined as the third target cut-out submodule. Assuming that the fourth energy storage submodule SM4 is cut out in this control cycle, in the next control cycle, the energy storage valve controller analyzes the target parameters of the energy storage submodules of the energy storage system and puts the fourth energy storage submodule SM4 into the energy storage system again. Assuming that the sorting result remains unchanged, in this case, the third energy storage submodule SM3 can be determined as the third target cut-out submodule.

[0153] S1423: If the submodule change amount is greater than 0, the sorting result of the previous control cycle is updated according to the submodule change amount to obtain an updated sorting result, and the first n energy storage submodules are determined as the third target input submodules according to the updated sorting result.

[0154] In the embodiment of the present application, if the submodule change is greater than 0, it means that the number of inputs in the current control cycle is greater than the number of inputs in the previous control cycle, that is, the current control cycle needs to put |Δn| energy storage submodules into the energy storage system.

[0155] In order to reduce the average switching frequency of the energy storage sub-module, when it is determined that |Δn| energy storage sub-modules need to be put into the energy storage system, the sorting result of the previous control cycle is first increased by |Δn| to obtain an updated sorting result, and then the first n energy storage sub-modules are determined as the third target input sub-modules according to the updated sorting result.

[0156] Exemplarily, assuming that the sorting result of the previous control cycle is {first energy storage submodule SM1, second energy storage submodule SM2, third energy storage submodule SM3, fourth energy storage submodule SM4, fifth energy storage submodule SM5, sixth energy storage submodule SM6}, the first energy storage submodule SM1, the second energy storage submodule SM2, and the third energy storage submodule SM3 have been put into operation, and assuming that |Δn| is 2, the sorting result of the previous control cycle is increased by |Δn|, and the updated sorting result is {third energy storage submodule SM3, fourth energy storage submodule SM4, fifth energy storage submodule SM5, sixth energy storage submodule SM6, first energy storage submodule SM1, second energy storage submodule SM2}, then this control cycle puts the third submodule SM3, the fourth submodule SM4, the fifth submodule SM5, the sixth submodule SM6, and the first submodule SM1 into operation.

[0157] It can be seen from the above that when the energy storage system is in a good balanced state, all energy storage sub-modules can be switched on and off in turn, reducing the average switching times of the energy storage sub-modules, reducing the average switching frequency of the sub-modules, and reducing the number of sorting times, thereby reducing the demand for the software and hardware resources of the energy storage valve controller.

[0158] In an embodiment of the present invention, the above-mentioned equalization method further includes:

[0159] Initialize the sorting of all energy storage submodules to obtain the initialization sorting result.

[0160] In an embodiment of the present application, at the beginning, the energy storage system can first initialize the sorting of all energy storage sub-modules, that is, obtain the priority of each energy storage sub-module in the energy storage system, and then sort the priorities of the energy storage sub-modules in descending order, so as to obtain the above-mentioned initialization sorting result.

[0161] For details about the priority of the energy storage submodule, please refer to the description of S131 and will not be elaborated here.

[0162] In the embodiment of the present application, the energy storage sub-modules are initialized at the beginning to obtain the initialization sorting results of each energy storage sub-module. When the uniformity deviation value of the energy storage system is small, the initialization sorting results obtained by initialization can be used to switch on and off the energy storage sub-modules in the energy storage system in turn, which can effectively reduce the number of sorting times of the controller and effectively reduce the demand for software and hardware resources of the energy storage sub-modules.

[0163] It should be understood that the size of the serial numbers of the steps in the above embodiments does not mean the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of the present application.

[0164] like Fig.12 As shown, another embodiment of the present application further provides an equalization device 12 , which includes: an acquisition module 121 , a determination module 122 , a first selection module 123 , a second selection module 124 and an operation module 125 .

[0165] The acquisition module 121 is used to acquire the target parameter value of each energy storage submodule.

[0166] The determination module 122 is used to determine the uniformity deviation value of the energy storage system according to the target parameter value of each energy storage submodule.

[0167] The first selection module 123 is used to determine the target switching submodule of the current control cycle according to a first selection strategy if the homogenization degree deviation is greater than or equal to the start threshold; the first selection strategy is set based on the equilibrium state of the target parameter.

[0168] The second selection module 124 is used to determine the target switching submodule of the current control cycle according to the second selection strategy if the homogenization degree deviation is less than the start threshold; the second selection strategy is set based on the average switching times of the energy storage submodule.

[0169] The operation module is used to perform a switching operation on the target switching submodule.

[0170] In one embodiment of the present application, the target switching submodule includes a first target input submodule, a second input submodule and a second switch-out submodule, and the first selection module includes a sorting unit, a first determination unit and a second determination unit.

[0171] The sorting unit is used to sort the target parameters of all energy storage submodules in descending order according to their priorities to obtain a sorting result.

[0172] The first determination unit is used to determine the first a energy storage submodules in the sorting result as the first target input submodules; wherein a is a positive integer.

[0173] The second determining unit is used to determine a second target input submodule or a second target cut-out submodule according to the input quantity of the current control cycle and the input quantity of the previous control cycle.

[0174] In one embodiment of the present application, the above-mentioned second determination unit is specifically used to: if the input quantity of the current control cycle is equal to the input quantity of the previous control cycle, determine that there is no second target input submodule and second target cut-out submodule; if the input quantity of the current control cycle is less than the input quantity of the previous control cycle, determine the second target cut-out submodule by cutting out the input submodule in turn; if the input quantity of the current control cycle is greater than the input quantity of the previous control cycle, determine the first |Δn| cut-out energy storage submodules of the sorting result as the second target input submodule; wherein Δn is the difference between the input quantity of the current control cycle and the input quantity of the previous control cycle.

[0175] In an embodiment of the present application, the acquisition module 121 is further used to re-acquire the target parameter value of each energy storage sub-module and recalculate the homogenization degree deviation.

[0176] The first selection module 123 further includes a judgment unit.

[0177] The above-mentioned judgment unit is used to determine that the current control cycle ends if the recalculated uniformity degree deviation is less than the return threshold, otherwise repeat the target step and the subsequent steps of the target step until the recalculated uniformity degree deviation is less than the return threshold; the target step is to sort the target parameters of all energy storage sub-modules in descending order according to their priorities to obtain the sorting result.

[0178] In one embodiment of the present application, the second selection module 124 further includes a third determination unit.

[0179] The third determination unit is used to determine the last b energy storage submodules in the sorting result as the first target cut-out submodules, where b is a positive integer.

[0180] In an embodiment of the present application, the third selection module 124 includes: a submodule change determination unit and a third determination unit.

[0181] The submodule change determination unit is used to determine the submodule change amount according to the input quantity of the current control cycle and the input quantity of the previous control cycle.

[0182] The third determining unit is used to determine a third target input submodule or a third target cutout submodule according to the submodule variation.

[0183] In one embodiment of the present application, the above-mentioned third determination unit is specifically used to determine that there is no third target input submodule and third target cut-out submodule if the submodule change amount is 0; if the submodule change amount is less than 0, the third target cut-out submodule is determined in a rotational manner according to the sorting result of the previous control cycle; if the submodule change amount is greater than 0, the sorting result of the previous control cycle is updated according to the submodule change amount to obtain an updated sorting result, and the first n energy storage submodules are determined as the third target input submodule according to the updated sorting result; wherein n is the number of submodules required to be put into operation in the current control cycle.

[0184] In an embodiment of the present application, the equalization device 12 further includes an initialization module.

[0185] The initialization module is used to initialize the sorting of all energy storage submodules to obtain the initialization sorting result.

[0186] Another embodiment of the present application further provides a terminal device, which may be a storage valve controller. The terminal device includes a memory, a processor, and a computer program stored in the memory and executable on the processor. The processor executes the program to implement the balancing method of any of the above-mentioned embodiments.

[0187] For example, Fig.13 Schematic diagram of a terminal device provided by an embodiment of the present application. Fig.13 As shown, the terminal device 13 provided in this embodiment includes: a processor 130, a memory 131, and a computer program 132 stored in the memory 131 and executable on the processor 130. When the processor 130 executes the computer program 132, the steps in the above-mentioned various equalization method embodiments are implemented, for example Figure 6 S11 to S15 shown.

[0188] Exemplarily, the computer program 132 may be divided into one or more modules / units, which are stored in the memory 131 and executed by the processor 130 to complete the present application. The one or more modules / units may be a series of computer program instruction segments that can complete specific functions, and the instruction segments are used to describe the execution process of the computer program 132 in the terminal device 13. For example, the computer program 132 may be divided into multiple units, and the specific functions of each unit may be described in detail in the following table. Fig.12 The relevant descriptions in the corresponding embodiments are not repeated here.

[0189] The terminal device may include, but is not limited to, a processor 130 and a memory 131. Those skilled in the art will appreciate that Fig.13It is only an example of the terminal device 13 and does not constitute a limitation on the terminal device 13. It may include more or fewer components than shown in the figure, or a combination of certain components, or different components. For example, the terminal device may also include input and output devices, network access devices, buses, etc.

[0190] The processor 130 may be a central processing unit (CPU), or other general-purpose processors, digital signal processors (DSP), application-specific integrated circuits (ASIC), field-programmable gate arrays (FPGA), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. A general-purpose processor may be a microprocessor or any conventional processor, etc.

[0191] The memory 131 may be an internal storage unit of the terminal device 13, such as a hard disk or memory of the terminal device 11. The memory 131 may also be an external storage device of the terminal device 13, such as a plug-in hard disk, a smart media card (SMC), a secure digital (SD) card, a flash card, etc. equipped on the terminal device 21. Further, the memory 131 may also include both an internal storage unit of the terminal device 13 and an external storage device. The memory 131 is used to store the computer program and other programs and data required by the terminal device. The memory 131 may also be used to temporarily store data that has been output or is to be output.

[0192] The terminal device provided in the embodiment of the present application and the method provided in the embodiment of the present application are based on the same inventive concept and have the same beneficial effects as the method adopted, operated or implemented by them.

[0193] Another embodiment of the present application provides an energy storage system, including the terminal device provided in the above embodiment. The energy storage system may also include an energy storage submodule, and the above terminal device executes the balancing method provided in the embodiment of the present application to achieve balancing of the energy storage submodule.

[0194] The embodiment of the present application further provides a computer-readable storage medium. The computer-readable storage medium stores a computer program, and when the computer program is executed by a processor, the balancing method in the above method embodiment can be implemented.

[0195] Examples of computer-readable storage media may include, but are not limited to, optical disks, phase change memory (PRAM), static random access memory (SRAM), dynamic random access memory (DRAM), other types of random access memory (RAM), read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), flash memory, or other optical or magnetic storage media, which are not listed here one by one.

[0196] The embodiment of the present application provides a computer program product. When the computer program product runs on a terminal device, the terminal device can implement the above-mentioned balancing method when executing the computer program product.

[0197] The computer-readable storage medium and computer program product provided in the embodiments of the present application are based on the same inventive concept as the method provided in the embodiments of the present application, and have the same beneficial effects as the method adopted, run or implemented by them.

[0198] The technicians in the relevant field can clearly understand that for the convenience and simplicity of description, only the division of the above-mentioned functional units and modules is used as an example. In actual applications, the above-mentioned function allocation can be completed by different functional units and modules as needed, that is, the internal structure of the terminal device can be divided into different functional units or modules to complete all or part of the functions described above. The functional units and modules in the embodiment can be integrated into a processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit. The above-mentioned integrated unit can be implemented in the form of hardware or in the form of software functional units. In addition, the specific names of the functional units and modules are only for the convenience of distinguishing each other, and are not used to limit the scope of protection of this application. The specific working process of the units and modules in the above-mentioned system can refer to the corresponding process in the aforementioned method embodiment, which will not be repeated here.

[0199] In the above embodiments, the description of each embodiment has its own emphasis. For parts that are not described or recorded in detail in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0200] Those of ordinary skill in the art will appreciate that the units and algorithm steps of each example described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Professional and technical personnel can use different methods to implement the described functions for each specific application, but such implementation should not be considered to be beyond the scope of this application.

[0201] The embodiments described above are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application has been described in detail with reference to the aforementioned embodiments, a person skilled in the art should understand that the technical solutions described in the aforementioned embodiments may still be modified, or some of the technical features may be replaced by equivalents. Such modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present application, and should all be included in the protection scope of the present application.

Claims

1. A balancing method, characterized in that: include: Obtain target parameter values ​​for each energy storage submodule; Determining a homogenization degree deviation value of the energy storage system according to the target parameter values ​​of each of the energy storage submodules; If the homogenization degree deviation is greater than or equal to the start threshold, determining the target switching submodule of the current control cycle according to the first selection strategy; The first selection strategy is set based on the equilibrium state of the target parameter; If the homogenization degree deviation is less than the start threshold, determining the target switching submodule of the current control cycle according to the second selection strategy; The second selection strategy is set based on the average switching times of the energy storage submodule; Perform a switching operation on the target switching submodule.

2. The equalization method according to claim 1, characterized in that: The target switching submodule includes a first target input submodule, a second input submodule and a second switch-out submodule. If the homogenization degree deviation is greater than or equal to the start threshold, the target switching submodule of the current control cycle is determined according to the first selection strategy, including: Sorting the target parameters of all the energy storage submodules in descending order according to their priorities to obtain a sorting result; Determine the first a energy storage submodules in the sorting result as the first target input submodule; wherein a is a positive integer; The second target input submodule or the second target cut-out submodule is determined according to the input quantity of the current control cycle and the input quantity of the previous control cycle.

3. The equalization method according to claim 2, characterized in that: The step of determining the second target input submodule or the second target cut-out submodule according to the input quantity of the current control cycle and the input quantity of the previous control cycle includes: If the input quantity of the current control cycle is equal to the input quantity of the previous control cycle, it is determined that the second target input submodule and the second target cut-out submodule do not exist; If the input quantity of the current control cycle is less than the input quantity of the previous control cycle, the second target cut-out submodule is determined by cutting out the input submodules in turn; If the number of inputs in the current control cycle is greater than the number of inputs in the previous control cycle, the first |Δn| cut-out energy storage submodules in the sorting result are determined as the second target input submodules; wherein Δn is the difference between the number of inputs in the current control cycle and the number of inputs in the previous control cycle.

4. The equalization method according to claim 2 or 3, characterized in that: After determining the second target input submodule or the second target cut-out submodule according to the input quantity of the current control cycle and the input quantity of the previous control cycle, the method further includes: Re-obtaining target parameter values ​​of each energy storage submodule, and recalculating the homogenization degree deviation; If the recalculated homogenization degree deviation is less than the return threshold, it is determined that the current control cycle is ended, otherwise the target step and the subsequent steps of the target step are repeated until the recalculated homogenization degree deviation is less than the return threshold; the target step is to sort the target parameters of all the energy storage sub-modules in descending order according to their priorities to obtain a sorting result.

5. The equalization method according to any one of claims 2 to 4, characterized in that: The target switching submodule includes a first target switching submodule, and if the homogenization degree deviation is greater than or equal to the start threshold, the target switching submodule of the current control cycle is determined according to the first selection strategy, including: Determine the last b energy storage submodules in the sorting result as the first target cut-out submodules, where b is a positive integer.

6. The equalization method according to any one of claims 2 to 5, characterized in that: The target switching submodule includes a third target input submodule and a third target cut-out submodule. If the homogenization degree deviation is less than the start threshold, the target switching submodule of the current control cycle is determined according to the second selection strategy, including: Determine the submodule change amount according to the input quantity of the current control cycle and the input quantity of the previous control cycle; A third target input submodule or a third target cutout submodule is determined according to the submodule change amount.

7. The equalization method according to claim 6, characterized in that: The step of determining a third target input submodule or a third target cutout submodule according to the submodule variation comprises: If the submodule change amount is 0, it is determined that the third target input submodule and the third target cut-out submodule do not exist; If the submodule change amount is less than 0, the third target submodule to be cut out is determined in a rotating cut-out manner according to the sorting result of the previous control cycle; If the submodule change is greater than 0, the sorting result of the previous control cycle is updated according to the submodule change to obtain an updated sorting result, and the first n energy storage submodules are determined as the third target investment submodules according to the updated sorting result; wherein n is the number of submodules required to be invested in the current control cycle.

8. The equalization method according to any one of claims 1 to 7, characterized in that: The balancing method further comprises: Initialize the sorting of all energy storage submodules to obtain the initialization sorting result.

9. A terminal device, characterized in that: The invention comprises a memory, a processor and a computer program stored in the memory and executable on the processor, wherein the processor implements the equalization method according to any one of claims 1 to 8 when executing the computer program.

10. An energy storage system, characterized in that: It comprises a plurality of energy storage submodules and the terminal device as claimed in claim 9.

11. A computer-readable storage medium storing a computer program, characterized in that: When the computer program is executed by a processor, the equalization method according to any one of claims 1 to 8 is implemented.

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