Photovoltaic energy storage active balancing method and energy storage balancing system

Abstract

The present invention relates to a photovoltaic energy storage active balancing method and an energy storage balancing system. The method is used for a control unit of an energy storage balancing system. The photovoltaic energy storage active balancing method includes: S1, determining whether an abnormality occurs in the energy storage balancing system; S2, if the energy storage balancing system does not occur, determining whether the energy storage balancing system has a charge or discharge request; S3, if the energy storage balancing system does not have a charge or discharge request, sorting multiple battery modules to obtain a sorting result; S4, performing active balancing according to the sorting result until the deviation of the state of charge between the multiple battery modules is less than the required balancing deviation, thereby completing active balancing. The solution described in the present application can effectively avoid the reduction of system capacity due to inconsistent SOC between modules, thereby maximizing the utilization of the system capacity.

Description

Technical Field

[0001] The present invention relates to the field of photovoltaic energy storage technology, and in particular to a photovoltaic energy storage active balancing method and an energy storage balancing system. Background Art

[0002] With the rapid development of the new energy industry in recent years, home photovoltaic energy storage systems have emerged. Existing stacked energy storage systems generally adopt a series connection mode, connecting multiple battery packs in series. However, it is difficult to achieve complete consistency between the voltage and state-of-charge (SOC) of the battery packs in existing designs, which introduces uncertainty to the full charging and discharging of the battery system. In addition, the balancing speed of passive balancing circuits is slow and cannot meet customer needs.

[0003] Based on the above technical scenarios, the industry needs to design a technical solution for active balancing of photovoltaic energy storage to help achieve balance between battery packs PACK, or to achieve rapid balancing when customers with needs expand the battery pack PACK, so that the system has more energy when charging or discharging, and more energy is stored in the battery or released, further utilizing energy. Summary of the Invention

[0004] The technical problem to be solved by the present invention is: how to design a solution for active balancing of photovoltaic energy storage, which can allow the system to have more energy when charging or discharging, so as to maximize the utilization of system capacity.

[0005] To solve the above problems, embodiments of the present invention provide a photovoltaic energy storage active balancing method and an energy storage balancing system, which can effectively avoid the reduction of system capacity due to SOC inconsistency between modules, thereby maximizing the utilization of system capacity.

[0006] In a first aspect, the present invention proposes a photovoltaic energy storage active balancing method, which is used for a control unit of an energy storage balancing system. The photovoltaic energy storage active balancing method includes: S1, determining whether an abnormality occurs in the energy storage balancing system; S2, if the energy storage balancing system does not occur, determining whether the energy storage balancing system has a charge or discharge request; S3, if the energy storage balancing system does not have a charge or discharge request, sorting multiple battery modules to obtain a sorting result; S4, performing active balancing according to the sorting result until the deviation of the charge state between the multiple battery modules is less than the balancing requirement deviation, thereby completing active balancing.

[0007] A further technical solution is that the energy storage balancing system also includes an alarm unit, and the control unit is connected to the alarm unit; after the step S1, determining whether the energy storage balancing system has an abnormality, the method further includes: if the energy storage balancing system has an abnormality, notifying the alarm unit of the energy storage balancing system and issuing a system alarm signal.

[0008] A further technical solution is that, in step S2, if the energy storage balancing system does not have any abnormality, after determining whether the energy storage balancing system has a charge or discharge request, the method further includes: if the energy storage balancing system has a charge or discharge request, continuing to maintain the normal operation of the energy storage balancing system.

[0009] Its further technical solution is that, in step S3, if the energy storage balancing system does not have a charge or discharge request, multiple battery modules are sorted to obtain a sorting result, including: if the energy storage balancing system does not have a charge or discharge request, multiple battery modules are sorted to obtain a battery module with the highest state of charge, a battery module with the second highest state of charge, and other n battery modules; the SOC parameter of the battery module with the highest state of charge corresponds to the current state of charge SOC1, the SOC parameter of the battery module with the second highest state of charge corresponds to the current state of charge SOC2, and the SOC parameters of the other n battery modules correspond to the current state of charge SOCn; the order of the current state of charge SOC1, the current state of charge SOC2, and the current state of charge SOCn is used as the sorting result. In the above solution, the current state of charge SOCn can be a series of values, specifically up to n SOC parameters.

[0010] Its further technical solution is that the step S4 performs active balancing according to the sorting result until the deviation of the state of charge between the multiple battery modules is less than the required deviation of balancing, and the active balancing is completed, including: starting the active balancing of the battery module with the highest state of charge, so that the deviation of the state of charge between the current state of charge SOC1 and the current state of charge SOC2 is less than the first preset deviation; starting the active balancing of the battery module with the highest state of charge and the battery module with the second highest state of charge, so that the deviation of the state of charge between the current state of charge SOC1, the current state of charge SOC2, and the current state of charge SOCn is less than the required deviation of balancing; obtaining the change of the value of the current state of charge SOC1 until the target state of charge SOC11 for balancing, obtaining the change of the value of the current state of charge SOC2 until the target state of charge SOC21 for balancing, obtaining the change of the value of the current state of charge SOCn until the target state of charge SOCn1 for balancing, and completing the active balancing. The solution of the above embodiment can be used in the discharge balancing process of the system, and based on the same principle and calculation method, it can also be used in the charge balancing process of the system.

[0011] In the above scheme, if only one balancing module is balancing at a time, the balancing current must take into account the module's own discharge current to the entire system. Furthermore, assuming the balancing power is Wb and the efficiency is η, the balancing module input current is Wb ÷ Vin, and the module output current is Wb*η ÷ Vout. Therefore, the balancing current is Wb / Vin - Wb*η / Vout. Similarly, for each module, namely battery module B101, battery module B102, multiple battery modules B10n, battery module B201, battery module B202, and multiple battery modules B20n, the balancing time required for each module is calculated to achieve balancing.

[0012] Its further technical solution is that the calculation process of the target state of charge SOC11 includes: target state of charge SOC11 = current state of charge SOC1-(current state of charge SOC1-current state of charge SOCn) / n; wherein, the target state of charge SOC11 is the SOC value of the battery module with the highest state of charge after system balancing.

[0013] Its further technical solution is that the calculation process of the target state of charge SOC21 includes: target state of charge SOC21 = current state of charge SOC2 + (current state of charge SOC1 - current state of charge SOCn) / n; wherein, the target state of charge SOC21 is the SOC value of a battery module with the second highest state of charge after system balancing.

[0014] Its further technical solution is that the calculation process of the target state of charge SOCn1 includes: target state of charge SOCn1 = current state of charge SOCn + (current state of charge SOC1 - current state of charge SOCn) / n; wherein, the target state of charge SOCn1 is the SOC value of a battery module with the second highest state of charge after system balancing.

[0015] In a second aspect, the present invention further proposes an energy storage balancing system, which is used to execute the photovoltaic energy storage active balancing method described in the first aspect, and the energy storage balancing system also includes: a battery module B101, a battery module B102, multiple battery modules B10n, a balancing module M101, a balancing module M102, multiple balancing modules M10n, and an inverter I NV; the battery module B101, the battery module B102, and multiple battery modules B10n are all connected to the inverter I NV; the balancing module M101, the balancing module M102, and multiple balancing modules M10n are all connected to the inverter I NV; the balancing module M101 is used to achieve active balancing and is connected to the battery module B101, the balancing module M102 is used to achieve active balancing and is connected to the battery module B102, and the balancing module M103 is used to achieve active balancing and is connected to the battery module B103.

[0016] Therefore, the beneficial effects of the present application include: first, a significant improvement in the efficiency of completing balancing; second, it can effectively avoid the reduction of system capacity due to SOC inconsistency between modules, thereby maximizing the utilization of the system capacity.

[0017] To sum up, it is difficult to achieve complete consistency between the battery pack PACK voltage and SOC in the existing design, which brings uncertainty to the full charging and discharging of the battery system, and the balancing speed of the passive balancing circuit is slow and cannot meet customer needs; based on the above technical scenarios, a photovoltaic energy storage active balancing method and energy storage balancing system proposed in this application can effectively avoid the reduction of system capacity due to inconsistent SOC between modules, thereby maximizing the utilization of the system capacity. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the invention and, together with the description, serve to explain the principles of the invention.

[0019] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, for ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0020] Figure 1 A schematic flow chart of a photovoltaic energy storage active balancing method provided in an embodiment of the present invention.

[0021] Figure 2 Another flowchart of the photovoltaic energy storage active balancing method provided by an embodiment of the present invention.

[0022] Figure 3 Another flowchart of the photovoltaic energy storage active balancing method provided by an embodiment of the present invention.

[0023] Figure 4 A circuit diagram of an energy storage balancing system provided in an embodiment of the present invention.

[0024] Figure 5 This is a schematic diagram of the SOC of the energy storage balancing system provided in an embodiment of the present invention. DETAILED DESCRIPTION

[0025] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making any creative efforts shall fall within the scope of protection of the present invention.

[0026] It will be understood that when used in this specification and the appended claims, the terms “include” and “comprising” indicate the presence of described features, integers, steps, operations, elements and / or components, but do not exclude the presence or addition of one or other features, integers, steps, operations, elements, components and / or collections thereof.

[0027] It should also be understood that the terms used in the present specification are only for the purpose of describing specific embodiments and are not intended to limit the present invention. As used in the present specification and the appended claims, the singular forms "a", "an" and "the" are intended to include the plural forms unless the context clearly indicates otherwise.

[0028] It should be further understood that the term "and / or" used in the present description and the appended claims refers to one or any combination and all possible combinations of the associated listed items, and includes these combinations.

[0029] As used in this specification and the appended claims, the term "if" can be interpreted as "when" or "upon" or "in response to determining" or "in response to detecting," depending on the context. Similarly, the phrase "if it is determined" or "if [described condition or event] is detected" can be interpreted as meaning "upon determination" or "in response to determining" or "upon detection of [described condition or event]" or "in response to detecting [described condition or event]," depending on the context.

[0030] Example

[0031] See also Figures 1 to 4 As shown, Figure 1An embodiment of the present invention provides a photovoltaic energy storage active balancing method, which is used in a control unit of an energy storage balancing system. The photovoltaic energy storage active balancing method includes:

[0032] S1, determine whether the energy storage balancing system is abnormal.

[0033] S2: If the energy storage balancing system does not have any abnormality, determine whether the energy storage balancing system has a charge or discharge request.

[0034] S3: If the energy storage balancing system has no charge or discharge request, sort the multiple battery modules to obtain a sorting result.

[0035] S4, performing active balancing according to the sorting result until the charge state deviation between the multiple battery modules is less than the balancing requirement deviation, and the active balancing is completed.

[0036] In the above solution, the charge state deviation between the multiple battery modules is smaller than the balance requirement deviation, wherein the balance requirement deviation means that a certain deviation is allowed, but the value of the deviation meets the balance requirement.

[0037] In one embodiment, the energy storage balancing system further includes an alarm unit, and the control unit is connected to the alarm unit; after the step S1, determining whether an abnormality occurs in the energy storage balancing system, the method further includes: if an abnormality occurs in the energy storage balancing system, notifying the alarm unit of the energy storage balancing system and issuing a system alarm signal.

[0038] In one embodiment, in step S2, if the energy storage balancing system does not have any abnormality, after determining whether the energy storage balancing system has a charge or discharge request, the method further includes: if the energy storage balancing system has a charge or discharge request, continuing to maintain the normal operation of the energy storage balancing system.

[0039] In one embodiment, in step S3, if the energy storage balancing system does not have a charge or discharge request, sorting the multiple battery modules to obtain a sorting result includes:

[0040] S301 : If the energy storage balancing system has no charge or discharge request, multiple battery modules are sorted to obtain a battery module with the highest state of charge, a battery module with the second highest state of charge, and other n battery modules.

[0041] S302 , the SOC parameter of the battery module with the highest state of charge corresponds to the current state of charge SOC1 , the SOC parameter of the battery module with the second highest state of charge corresponds to the current state of charge SOC2 , and the SOC parameters of the other n battery modules correspond to the current state of charge SOCn.

[0042] S303 , taking the order of the current state of charge SOC1 , the current state of charge SOC2 , and the current state of charge SOCn as a sorting result.

[0043] In one embodiment, step S4, performing active balancing according to the sorting result until the state of charge deviation between the plurality of battery modules is less than the required balancing deviation, completing active balancing, includes:

[0044] S401 , starting active balancing of a battery module with the highest state of charge, so that a state of charge deviation between a current state of charge SOC1 and a current state of charge SOC2 is smaller than a first preset deviation.

[0045] S402 , active balancing of a battery module with the highest state of charge and a battery module with the second highest state of charge is started, so that the deviation of the state of charge among the current state of charge SOC1 , the current state of charge SOC2 , and the current state of charge SOCn is less than the balancing requirement deviation.

[0046] S403, obtain the value change of the current state of charge SOC1 until the balanced target state of charge SOC11, obtain the value change of the current state of charge SOC2 until the balanced target state of charge SOC21, obtain the value change of the current state of charge SOCn until the balanced target state of charge SOCn1, and complete active balancing.

[0047] In the above scheme, the state of charge deviation between the current state of charge SOC1 and the current state of charge SOC2 is made smaller than the first preset deviation. Corresponding to the first round of balancing, only the deviation between the battery module B101 and the battery module B102 is considered to be smaller than the first preset deviation, without considering the parameters of the other multiple battery modules B10n.

[0048] In one embodiment, the target state of charge SOC11 calculation process includes:

[0049] Target state of charge SOC11 = current state of charge SOC1 - (current state of charge SOC1 - current state of charge SOCn) / n.

[0050] The target state of charge SOC11 is the SOC value of the battery module with the highest state of charge after system balancing.

[0051] In one embodiment, the target state of charge SOC21 calculation process includes:

[0052] Target state of charge SOC21 = current state of charge SOC2 + (current state of charge SOC1 - current state of charge SOCn) / n.

[0053] The target state of charge SOC21 is the SOC value of a battery module with the second highest state of charge after system balancing.

[0054] In one embodiment, the target state of charge SOCn1 is calculated as follows:

[0055] Target state of charge SOCn1 = current state of charge SOCn + (current state of charge SOC1 - current state of charge SOCn) / n.

[0056] The target state of charge SOCn1 is the SOC value of a battery module with the second highest state of charge after system balancing.

[0057] In one embodiment, see Figure 4 As shown, the present invention further proposes an energy storage balancing system, which is used to execute the photovoltaic energy storage active balancing method as described in any of the above embodiments. The energy storage balancing system also includes: a battery module B101, a battery module B102, multiple battery modules B10n, a balancing module M101, a balancing module M102, multiple balancing modules M10n, and an inverter I NV.

[0058] The battery module B101, the battery module B102, and multiple battery modules B10n are all connected to the inverter I NV; the balancing module M101, the balancing module M102, and multiple balancing modules M10n are all connected to the inverter INV; the balancing module M101 is used to achieve active balancing and is connected to the battery module B101, the balancing module M102 is used to achieve active balancing and is connected to the battery module B102, and the balancing module M103 is used to achieve active balancing and is connected to the battery module B103.

[0059] In the above solution, the energy storage balancing system includes battery module B101, battery module B102, multiple battery modules B10n, balancing modules M101, balancing modules M102, multiple balancing modules M10n, and inverter I NV. The balancing modules include a switch Q101, a transformer T101, and a rectifier diode D101. Battery module B101, battery module B102, and multiple battery modules B10n each contain multiple cells. The system includes multiple battery modules, balancing modules, switches, transformers, and rectifier diodes, each with a consistent number n. The specific balancing process includes the following methods: Method 1 and Method 2.

[0060] Method 1, discharge balancing process: After the system is turned on, determine whether the system has an abnormal alarm. If there is no abnormal alarm, check whether there is a charge and discharge request. If there is a charge and discharge request, run normally. If there is no charge and discharge request, obtain the SOC values ​​of multiple modules, including battery module B101, battery module B102, and multiple battery modules B10n. At the same time, obtain the minimum SOC value of a single cell in battery module B101, battery module B102, and multiple battery modules B10n. And compare this minimum SOC, assuming that the current state of charge SOC1> the current state of charge SOC2> the current state of charge SOCn, such as Figure 5 As shown, the active balancing module of battery module B101, namely balancing module M101, is activated to start discharging. It then continuously detects and determines whether the SOC difference between battery modules B101 and B102 meets the balancing requirement. If so, balancing stops; if not, balancing continues. Similarly, this discharge achieves balancing for battery module B101, battery module B102, and multiple battery modules B10n.

[0061] Method 2, charging balancing process: After the system is turned on, determine whether the system has an abnormal alarm. If there is no abnormal alarm, check whether there is a charge and discharge request. If there is a charge and discharge request, run normally. If there is no charge and discharge request, obtain the SOC values ​​of multiple modules, including battery module B201, battery module B202, and multiple battery modules B20n (here equivalent to the SOC values ​​of battery module B101, battery module B102, and multiple battery modules B10n). At the same time, obtain the minimum SOC value of a single cell in battery module B201, battery module B202, and multiple battery modules B20n. And compare this minimum SOC. Assume that SOC battery module B201> battery module B202> multiple battery modules B20n, such as Figure 5 As shown, the active balancing modules of the multiple battery modules B20n, namely the multiple balancing modules M20n, are activated to perform a discharge operation. The SOC difference between the multiple battery modules B20n and the battery module B202 is then continuously detected and determined to see if it meets the balancing requirement. If so, balancing is stopped; if not, balancing continues. Similarly, referring to the aforementioned method for achieving balancing by discharge, the battery modules can achieve balancing by charging.

[0062] To sum up, it is difficult to achieve complete consistency between the battery pack PACK voltage and SOC in the existing design, which brings uncertainty to the full charging and discharging of the battery system, and the balancing speed of the passive balancing circuit is slow and cannot meet customer needs; based on the above technical scenarios, a photovoltaic energy storage active balancing method and energy storage balancing system proposed in this application can effectively avoid the reduction of system capacity due to inconsistent SOC between modules, thereby maximizing the utilization of the system capacity.

[0063] Those skilled in the art will appreciate that the units and algorithm steps of each example described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, computer software, or a combination of the two. In order to clearly illustrate the interchangeability of hardware and software, the above description has generally described the components and steps of each example according to their functions. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Professionals and technicians can use different methods to implement the described functions, but such implementation should not be considered to be beyond the scope of the present invention.

[0064] In the several embodiments provided herein, it should be understood that the disclosed devices and methods can be implemented in other ways. For example, the device embodiments described above are merely illustrative. For example, the division of the various units is merely a logical functional division, and actual implementation may employ other division methods. For example, units or components may be combined or integrated into another system, or some features may be omitted or not implemented.

[0065] The steps in the methods of the embodiments of the present invention may be adjusted in order, combined, or deleted as needed. The units in the devices of the embodiments of the present invention may be combined, divided, or deleted as needed. Furthermore, the functional units in the various embodiments of the present invention may be integrated into a single processing unit, each unit may exist physically separately, or two or more units may be integrated into a single unit.

[0066] If this integrated unit is implemented as a software functional unit and sold or used as an independent product, it can be stored in a storage medium. Based on this understanding, the technical solution of the present invention, or the part that contributes to the existing technology, or all or part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes a number of instructions for causing a computer device (which can be a personal computer, terminal, or network device, etc.) to execute all or part of the steps of the method described in various embodiments of the present invention.

[0067] In the above embodiments, the description of each embodiment has its own focus. For parts that are not described in detail in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0068] Obviously, those skilled in the art may make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, to the extent such changes and modifications fall within the scope of the claims and their equivalents, the present invention is intended to encompass such changes and modifications.

[0069] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any person skilled in the art can easily conceive of various equivalent modifications or substitutions within the technical scope disclosed in the present invention, and such modifications or substitutions are intended to be within the scope of protection of the present invention. Therefore, the scope of protection of the present invention shall be subject to the scope of protection of the claims.

Claims

1. A photovoltaic energy storage active balancing method, characterized in that: The method is used for a control unit of an energy storage balancing system, and the photovoltaic energy storage active balancing method includes: S1, determine whether the energy storage balancing system is abnormal; S2, if the energy storage balancing system does not have any abnormality, determining whether the energy storage balancing system has a charge or discharge request; S3, if the energy storage balancing system has no charge or discharge request, sorting the multiple battery modules to obtain a sorting result; specifically comprising: if the energy storage balancing system has no charge or discharge request, sorting the multiple battery modules to obtain a battery module with the highest state of charge, a battery module with the second highest state of charge, and n other battery modules; corresponding the SOC parameter of the battery module with the highest state of charge to the current state of charge SOC1, corresponding the SOC parameter of the battery module with the second highest state of charge to the current state of charge SOC2, and corresponding the SOC parameters of the other n battery modules to the current state of charge SOCn; and using the order of the current state of charge SOC1, the current state of charge SOC2, and the current state of charge SOCn as the sorting result; S4, performing active balancing according to the sorting result until the deviation of the states of charge between the multiple battery modules is less than the required deviation for balancing, thereby completing active balancing; specifically comprising: starting active balancing of a battery module with the highest state of charge, so that the deviation of the states of charge between the current state of charge SOC1 and the current state of charge SOC2 is less than a first preset deviation; starting active balancing of a battery module with the highest state of charge and a battery module with the second highest state of charge, so that the deviation of the states of charge between the current states of charge SOC1, the current states of charge SOC2, and the current states of charge SOCn is less than the required deviation for balancing; obtaining a value change of the current state of charge SOC1 until the target state of charge SOC11 for balancing, obtaining a value change of the current state of charge SOC2 until the target state of charge SOC21 for balancing, obtaining a value change of the current state of charge SOCn until the target state of charge SOCn1 for balancing, thereby completing active balancing; The calculation process of the target state of charge SOC11 includes: Target state of charge SOC11 = current state of charge SOC1 - (current state of charge SOC1 - current state of charge SOCn) / n; The target state of charge SOC11 is the SOC value of the battery module with the highest state of charge after system balancing; The calculation process of the target state of charge SOC21 includes: Target state of charge SOC21 = current state of charge SOC2 + (current state of charge SOC1 - current state of charge SOCn) / n; The target state of charge SOC21 is the SOC value of a battery module with the second highest state of charge after system balancing; The target state of charge SOCn1 calculation process includes: Target state of charge SOCn1 = current state of charge SOCn + (current state of charge SOC1 - current state of charge SOCn) / n; The target state of charge SOCn1 is the SOC value of a battery module with the second highest state of charge after system balancing.

2. The photovoltaic energy storage active balancing method according to claim 1, characterized in that: The energy storage balancing system further includes an alarm unit, and the control unit is connected to the alarm unit. After determining whether an abnormality occurs in the energy storage balancing system in step S1, the method further includes: If an abnormality occurs in the energy storage balancing system, the alarm unit of the energy storage balancing system is notified and a system alarm signal is issued.

3. The photovoltaic energy storage active balancing method according to claim 2, characterized in that: In step S2, if the energy storage balancing system does not have any abnormality, after determining whether the energy storage balancing system has a charge or discharge request, the method further includes: If the energy storage balancing system has a charge or discharge request, the normal operation of the energy storage balancing system is continued.

4. An energy storage balancing system, characterized in that: The energy storage balancing system is used to execute the photovoltaic energy storage active balancing method according to any one of claims 1 to 3, and the energy storage balancing system further includes: Battery module B101, battery module B102, multiple battery modules B10n, balancing module M101, balancing module M102, multiple balancing modules M10n, inverter INV; The battery module B101, the battery module B102, and the plurality of battery modules B10n are all connected to the inverter INV; the balancing module M101, the balancing module M102, and the plurality of balancing modules M10n are all connected to the inverter INV; The balancing module M101 is used to implement active balancing and is connected to the battery module B101 , the balancing module M102 is used to implement active balancing and is connected to the battery module B102 , and the balancing module M103 is used to implement active balancing and is connected to the battery module B103 .

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