Lithium battery capacity supplement device and energy storage system

Abstract

The utility model provides a lithium battery capacity supplement device and an energy storage system, and relates to the technical field of lithium batteries, the device comprises at least one first battery unit and a switch module; the lithium battery capacity supplement device is in communication connection with a battery system controller BSC of the energy storage system body; the first battery unit is connected with the second battery unit in the energy storage system body in parallel through the corresponding switch module, and the switch module is used for controlling whether the corresponding first battery unit is connected into the energy storage system body or not. The service life of the system where the lithium battery is located and the maintenance cost of the system can be considered.

Description

Technical Field

[0001] The utility model relates to the technical field of lithium batteries, and more specifically, to a lithium battery capacity supplement device and an energy storage system. Background Art

[0002] At present, the capacity of lithium batteries will decay due to factors such as age and the increase in charge and discharge times, making them unable to meet the original design requirements. In order to solve this problem, lithium battery maintenance personnel can directly increase the capacity of the original lithium battery.

[0003] However, in the above solution, when the capacity of the lithium battery is increased too much at one time, the service life of the system in which the lithium battery is located will be affected. When only the attenuated capacity of the lithium battery is supplemented, the capacity needs to be supplemented frequently, which makes the system maintenance cost high.

[0004] Based on this, how to balance the service life of the system where the lithium battery is located and the maintenance cost of the system has become a technical problem that needs to be solved urgently. Utility Model Content

[0005] In order to solve the above technical problems, the utility model provides a lithium battery capacity supplement device and an energy storage system.

[0006] In order to achieve the above purpose, the utility model provides the following technical solutions:

[0007] The utility model provides a lithium battery capacity supplement device, comprising: at least one first battery unit and a switch module;

[0008] The lithium battery capacity supplement device is communicatively connected with the battery system controller BSC of the energy storage system body;

[0009] The first battery unit is connected in parallel with the second battery unit in the energy storage system body through the corresponding switch module, and the switch module is used to control whether the corresponding first battery unit is connected to the energy storage system body.

[0010] Optionally, the switch module is a DC / DC conversion circuit.

[0011] Optionally, the switch module is a controllable switch, and its on-off is controlled by the BSC.

[0012] Optionally, the number of the first battery cells is greater than or equal to 2.

[0013] Optionally, the capacities of the first battery cells are equal.

[0014] Optionally, the capacities of at least two of the first battery cells are different.

[0015] Optionally, the lithium battery capacity supplement device of the utility model further includes: at least one battery capacity supplement cabinet;

[0016] Each of the first battery units and the switch module thereof are located in the same battery capacity supplement cabinet; or, there are at least two of the first battery units and the switch modules thereof, which are respectively located in different battery capacity supplement cabinets.

[0017] The utility model also provides an energy storage system, comprising: an energy storage system body and the lithium battery capacity supplement device as described above;

[0018] The energy storage system body includes a BSC and at least one second battery unit;

[0019] The BSC is communicatively connected with the second battery unit;

[0020] When the number of the second battery units is greater than 1, each of the second battery units is connected to the external DC bus through a bus bar;

[0021] When the capacity attenuation of the energy storage system body is greater than a preset attenuation threshold, at least one switch module in the lithium battery capacity supplement device is controlled to be turned on.

[0022] Optionally, the energy storage system body and the lithium battery capacity supplement device are arranged in the same cabinet.

[0023] Optionally, the energy storage system body and the lithium battery capacity supplement device are arranged in different cabinets.

[0024] It can be seen from the above technical solution that the lithium battery capacity supplement device provided by the utility model includes: at least one first battery unit and a switch module; the lithium battery capacity supplement device is connected to the battery system controller BSC of the energy storage system body in communication; the first battery unit is connected in parallel with the second battery unit in the energy storage system body through the corresponding switch module, and the switch module is used to control whether the corresponding first battery unit is connected to the energy storage system body. Based on this, the BSC can directly or indirectly control the on and off of the switch module by communicating with the lithium battery capacity supplement device, thereby controlling whether the first battery unit is connected to the energy storage system body.

[0025] This enables the BSC to close the target switch module in all switch modules according to the capacity attenuation of the energy storage system body when it determines that the capacity of the energy storage system body does not meet the preset capacity requirements, so that the target first battery unit corresponding to the target switch module supplements the capacity of the energy storage system body. Among them, the difference between the total supplementary capacity corresponding to all target first battery units and the capacity attenuation of the energy storage system body is less than the preset difference threshold, thus avoiding adding too much capacity to the energy storage system body and ensuring the service life of the energy storage system; and, because the utility model can realize automatic capacity supplementation according to the capacity attenuation of the energy storage system body, the utility model can avoid frequent manual capacity supplementation and reduce the maintenance cost of the energy storage system. It can be seen that the utility model can take into account both the service life of the system where the lithium battery is located and the maintenance cost of the system. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] In order to more clearly illustrate the embodiments of the utility model or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings in the following description are only embodiments of the utility model. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without paying creative work.

[0027] Figure 1 This is a schematic diagram of the structure of a lithium battery capacity supplement device provided by an embodiment of the utility model;

[0028] Figure 2 It is a structural schematic diagram of another lithium battery capacity supplement device provided by an embodiment of the utility model;

[0029] Figure 3 It is a structural schematic diagram of another lithium battery capacity supplement device provided by an embodiment of the utility model;

[0030] Figure 4 It is a structural schematic diagram of an energy storage system provided by an embodiment of the utility model. DETAILED DESCRIPTION

[0031] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0032] At present, the capacity of lithium batteries will decay due to factors such as age and the increase in charge and discharge times, making them unable to meet the original design requirements. To solve this problem, lithium battery maintenance personnel can replace all lithium batteries with new ones. However, this method is costly and the usable part of the original lithium battery is wasted, resulting in a waste of lithium battery resources.

[0033] In order to reduce the cost of lithium battery capacity replenishment and avoid the problem of lithium battery resource waste, lithium battery maintenance personnel can also directly increase part of the capacity of the original lithium battery. However, in this solution, when a large amount of capacity is added at one time, due to the excessively high capacity of the lithium battery, the relevant parameters of the system where the lithium battery is located may not meet the design requirements of the original system, thereby affecting the service life of the system; when only the attenuated part is replenished each time, lithium battery maintenance personnel are required to frequently replenish the capacity, which has high manual maintenance costs.

[0034] Based on this, in order to take into account the service life of the system where the lithium battery is located and the maintenance cost of the system, the utility model provides a lithium battery capacity supplement device and an energy storage system. The technical solution of the utility model is described in detail below in conjunction with the accompanying drawings.

[0035] Figure 1 Schematic diagram of the structure of a lithium battery capacity supplement device provided by the embodiment of the utility model. Figure 1 As shown, the lithium battery capacity supplement device 11 includes: at least one first battery unit 101 and a switch module 102 thereof.

[0036] Among them, the lithium battery capacity supplement device 11 is connected to the battery system controller (Battery System Controller, BSC) of the energy storage system body. Specifically, the switch module 102 can be connected to the BSC through the corresponding communication line, and the BSC can directly control the on-off state of the switch module 102. Secondly, the lithium battery capacity supplement device 11 can also be provided with a controller, and the controller is respectively connected to the BSC and the switch module 102 for communication, and the BSC can indirectly control the on-off state of the switch module 102 through the controller, that is, the BSC sends a control instruction to the controller, and the controller controls the on-off state of the switch module 102 according to the control instruction.

[0037] The first battery unit 101 is connected in parallel with the second battery unit in the energy storage system body through the corresponding switch module 102. The switch module is used to control whether the corresponding first battery unit is connected to the energy storage system body. Therefore, when any switch module 102 is closed, the first battery unit 101 connected to the switch module 102 enters the capacity supplement state and supplements the capacity of the energy storage system body.

[0038] In actual application, when the BSC determines that the capacity of the energy storage system does not meet the preset capacity requirements, it can select the target first battery cell 101 that needs to enter the capacity supplement state from all the first battery cells 101 according to the capacity attenuation of the energy storage system. The number of target first battery cells 101 can be at least one, and the difference between the total supplementary capacity corresponding to all target first battery cells 101 and the capacity attenuation of the energy storage system is less than the preset difference threshold. In this way, it is avoided to increase the capacity of the energy storage system too much, so that the capacity of the energy storage system is always consistent or relatively consistent with the design capacity, and the stability of the relevant system parameters is improved, thereby extending the service life of the energy storage system, increasing the benefits of the energy storage system, and improving the stability and reliability of the energy storage system. Then, the switch module 102 corresponding to the target first battery cell 101 is closed to make the target first battery cell 101 enter the capacity supplement state.

[0039] Furthermore, since the embodiment of the utility model can realize automatic capacity replenishment according to the capacity attenuation of the energy storage system itself, the embodiment of the utility model can avoid frequent manual capacity replenishment, thereby reducing the maintenance cost of the energy storage system; and, since the operation state of the energy storage system needs to be interrupted when manual capacity replenishment is performed, while the embodiment of the utility model does not need to interrupt the operation state of the energy storage system when automatic capacity replenishment is performed, therefore, the embodiment of the utility model can also improve the rate of return of the energy storage system.

[0040] It should be noted that the BSC can determine that the capacity of the energy storage system body does not meet the preset capacity requirements when it is determined that the energy storage system body has capacity attenuation. In addition, the BSC can also calculate the capacity attenuation of the energy storage system body when it is determined that the energy storage system body has capacity attenuation, and determine whether the capacity attenuation is greater than the preset attenuation threshold. If the capacity attenuation is greater than the preset attenuation threshold, it is determined that the capacity of the energy storage system body does not meet the preset capacity requirements. If the capacity attenuation is not greater than the preset attenuation threshold, it is determined that the capacity of the energy storage system body meets the preset capacity requirements. In this way, the frequency of capacity replenishment can be reduced, thereby reducing the maintenance cost of the system.

[0041] And, it should be noted that the BSC can preferentially make the total supplementary capacity corresponding to all target first battery cells 101 equal to the capacity attenuation of the energy storage system body, when the total supplementary capacity corresponding to all target first battery cells 101 cannot be equal to the capacity attenuation of the energy storage system body, so that the difference between the total supplementary capacity corresponding to all target first battery cells 101 and the capacity attenuation of the energy storage system body is less than a preset difference threshold.

[0042] In a specific example, the supplementary capacity corresponding to each first battery unit 101 is 0.5MWh, and the capacity attenuation of the energy storage system is 2MWh. In this case, the BSC controls any four first battery units 101 to supplement the capacity, and the total supplementary capacity corresponding to any four first battery units 101 is equal to the capacity attenuation of the energy storage system.

[0043] In another specific example, the supplementary capacity corresponding to each first battery unit 101 is 0.5MWh, and the capacity attenuation of the energy storage system is 1.8MWh. In this case, it is impossible to achieve a total supplementary capacity equal to the capacity attenuation of the energy storage system. The BSC can control any four first battery units 101 to supplement the capacity. At this time, the total supplementary capacity is equal to 2MWh, which is greater than the capacity attenuation of the energy storage system. Secondly, any three first battery units 101 can also be controlled to supplement the capacity. At this time, the total supplementary capacity is equal to 1.5MWh, which is less than the capacity attenuation of the energy storage system.

[0044] In the embodiment of the utility model, the switch module may be a DC / DC conversion circuit.

[0045] Specifically, when the difference between the output voltage of the first battery unit 101 and the voltage of the bus connected to the second battery unit is large, in this case, if the switch module 102 connected to the first battery unit 101 is directly closed, a circuit failure is likely to occur. Therefore, the switch module can be a DC / DC conversion circuit. In this way, after the BSC determines the target switch module 102 that needs to be closed, it can send the voltage of the bus connected to the second battery unit to the target switch module 102. After any target switch module 102 receives the voltage of the bus connected to the second battery unit, the target switch module 102 will convert the output voltage of the first battery unit 101 connected to it into the voltage of the bus connected to the second battery unit. For example, if the voltage of the bus connected to the second battery unit is 1220V and the original output voltage of the first battery unit 101 is 1100V, the output voltage of the first battery unit 101 is converted to 1220V. After completing the output voltage conversion, the target switch module 102 controls the corresponding first battery unit 101 to be connected to the energy storage system body, so that it supplements the capacity of the energy storage system body.

[0046] It should be noted that the switch module can also be other modules that can realize the original output voltage conversion of the first battery unit and the corresponding circuit connection state. The embodiment of the utility model is not specifically limited here, and it is sufficient to realize the embodiment of the utility model.

[0047] In the embodiment of the utility model, the switch module may also be a controllable switch, and its on and off is controlled by the BSC.

[0048] Specifically, the controllable switch is any switch in the prior art that can implement the present application. For example, the controllable switch can be an intelligent switch in the prior art, and the present application does not make any specific limitation here.

[0049] In actual application, after the BSC determines the target switch module 102 that needs to be closed, the BSC can directly control the target switch module 102 to be closed, so that the corresponding first battery unit can supplement the capacity of the energy storage system body.

[0050] In the embodiment of the present invention, the number of the first battery units may be greater than or equal to 2.

[0051] In this case, the capacity of each first battery cell can be equal. In this way, when calculating the target first battery cell that needs to enter the capacity supplement state according to the capacity attenuation of the energy storage system, the calculation process is simple, which is conducive to improving the selection efficiency of the target first battery cell.

[0052] In addition, there may be at least two first battery cells with different capacities, so that the flexibility of the supplementary capacity of the lithium battery capacity supplement device can be improved, and the degree of fit between the supplementary capacity of the lithium battery capacity supplement device and the capacity attenuation of the energy storage system body can be improved. For example, assuming that there are five first battery cells, of which the supplementary capacity of three first battery cells is 0.5MWh, and the supplementary capacity of the remaining two first battery cells is 0.1MWh. In this way, when the capacity attenuation of the energy storage system body is 0.6MWh, a first battery cell with a supplementary capacity of 0.5MWh and a first battery cell with a supplementary capacity of 0.1MWh can be selected to supplement the capacity of the energy storage system body. In this case, the supplementary capacity of the lithium battery capacity supplement device and the capacity attenuation of the energy storage system body are both 0.6MWh, and the two are completely consistent.

[0053] In the embodiment of the utility model, the lithium battery capacity supplement device of the utility model may further include: at least one battery capacity supplement cabinet.

[0054] Each first battery unit and its switch module are located in the same battery capacity supplement cabinet; or, there are at least two first battery units and their switch modules, which are respectively located in different battery capacity supplement cabinets.

[0055] In a specific example, Figure 2 Schematic diagram of another lithium battery capacity supplement device provided by the present utility model. Figure 2 As shown, the number of battery capacity supplement cabinets 21 is equal to 1. In this case, each first battery unit and its switch module are located in the same battery capacity supplement cabinet. In this way, it is convenient to install the lithium battery capacity supplement device and can reduce the production cost of the lithium battery capacity supplement device.

[0056] In addition, the number of battery capacity supplement cabinets can be greater than or equal to 2. In this case, there are at least two first battery units and their switch modules, which are respectively located in different battery capacity supplement cabinets. In this way, when a battery capacity supplement cabinet and its internal components fail, they can be repaired separately without affecting the normal operation of other battery capacity supplement cabinets, which is conducive to improving the reliability and work efficiency of the lithium battery capacity supplement device.

[0057] In a specific example, Figure 3 Schematic diagram of another lithium battery capacity supplement device provided by the present utility model. Figure 3 As shown, the lithium battery capacity supplement device 11 is provided with two battery capacity supplement cabinets 21, one of which is provided with two first battery units 101 and a switch module 102 thereof, and the other is provided with one first battery unit 101 and a switch module 102 thereof.

[0058] Based on a general inventive concept, the utility model also provides an energy storage system. Figure 4 Schematic diagram of the structure of an energy storage system provided by the embodiment of the utility model. Figure 4 As shown, the energy storage system includes: an energy storage system body 41 and the lithium battery capacity supplement device 11 as described above.

[0059] The energy storage system body 41 includes a BSC 401 and at least one second battery unit 402 .

[0060] The BSC 401 is in communication connection with the second battery unit 402 .

[0061] When the number of the second battery units 402 is greater than 1, each second battery unit 402 is connected to the external DC bus through the bus bar 403 .

[0062] When the capacity attenuation of the energy storage system body is greater than a preset attenuation threshold, at least one switch module in the lithium battery capacity supplement device is controlled to be turned on.

[0063] In actual application, BSC 401 obtains the capacity of the energy storage system body 41 by analyzing the capacity of each second battery unit 402. When BSC 401 analyzes that the capacity of the energy storage system body 41 does not meet the preset capacity requirement (that is, when the capacity attenuation of the energy storage system body is greater than the preset attenuation threshold), it controls the lithium battery capacity supplement device 11 to supplement the capacity of the energy storage system body 41. The specific control method is referred to in the above embodiment and will not be repeated here. Among them, the preset attenuation threshold is a value greater than or equal to 0, and its specific value can be freely determined according to the actual situation, and the utility model does not make specific restrictions here.

[0064] The embodiment of the utility model adopts the above-mentioned technical solution, and obtains the energy storage system of the embodiment of the utility model by adding a lithium battery capacity supplement device on the basis of the energy storage system body of the prior art. In this way, the energy storage system of the embodiment of the utility model can automatically supplement the capacity when the capacity of the energy storage system body does not meet the preset capacity requirement, and then can automatically make the capacity of the energy storage system body always consistent or relatively consistent with the design capacity, which is conducive to extending the service life of the energy storage system, increasing the income of the energy storage system, improving the stability and reliability of the energy storage system, and reducing the maintenance cost of the energy storage system.

[0065] In the embodiment of the utility model, the energy storage system body 41 and the lithium battery capacity supplement device 11 can be arranged in the same cabinet, so as to facilitate the installation of the energy storage system.

[0066] In the embodiment of the utility model, the energy storage system body 41 and the lithium battery capacity supplement device 11 can also be arranged in different cabinets. In this way, the energy storage system body and the lithium battery capacity supplement device can be installed and used separately or as a set, making the application of the energy storage system more flexible.

[0067] It should be noted that each embodiment in this specification is described in a progressive manner, and each embodiment focuses on the differences from other embodiments, and the same or similar parts between the embodiments can be referenced to each other. The modules and submodules in the devices and terminals of each embodiment of the utility model can be merged, divided and deleted according to actual needs, and the features recorded in each embodiment can be replaced or combined.

[0068] In the several embodiments provided by the present utility model, it should be understood that the disclosed terminals and devices can be implemented in other ways. For example, the division of modules or submodules is only a logical function division, and there may be other division methods in actual implementation, such as multiple submodules or modules can be combined or integrated into another module, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be an indirect coupling or communication connection through some interfaces, devices or modules, which can be electrical, mechanical or other forms.

[0069] The modules or submodules described as separate components may or may not be physically separated, and the components of the modules or submodules may or may not be physical modules or submodules, that is, they may be located in one place, or they may be distributed on multiple network modules or submodules. Some or all of the modules or submodules may be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0070] In addition, each functional module or sub-module in each embodiment of the present invention may be integrated into one processing module, or each module or sub-module may exist physically separately, or two or more modules or sub-modules may be integrated into one module.

[0071] Finally, it should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "comprises", "comprising" or any other variants thereof are intended to cover non-exclusive inclusion, so that an article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such article or device. In the absence of further restrictions, the elements defined by the sentence "comprising a ..." do not exclude the existence of other identical elements in the article or device including the elements.

[0072] The above description of the disclosed embodiments enables those skilled in the art to implement or use the present invention. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but will conform to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A lithium battery capacity supplement device, characterized in that: include: at least one first battery unit and a switch module; The lithium battery capacity supplement device is communicatively connected with the battery system controller BSC of the energy storage system body; The first battery unit is connected in parallel with the second battery unit in the energy storage system body through the corresponding switch module, and the switch module is used to control whether the corresponding first battery unit is connected to the energy storage system body.

2. The lithium battery capacity supplement device according to claim 1, characterized in that: The switch module is a DC / DC conversion circuit.

3. The lithium battery capacity supplement device according to claim 1, characterized in that: The switch module is a controllable switch, and its on and off is controlled by the BSC.

4. The lithium battery capacity supplement device according to claim 1, characterized in that: The number of the first battery cells is greater than or equal to 2.

5. The lithium battery capacity supplement device according to claim 4, characterized in that: The capacities of the first battery cells are equal.

6. The lithium battery capacity supplement device according to claim 4, characterized in that: The capacities of at least two of the first battery cells are different.

7. The lithium battery capacity supplement device according to any one of claims 1 to 6, characterized in that: Also includes: At least one battery capacity supplement cabinet; Each of the first battery units and the switch module thereof are located in the same battery capacity supplement cabinet; Alternatively, there are at least two of the first battery units and the switch modules thereof, which are respectively located in different battery capacity supplement cabinets.

8. An energy storage system, characterized in that: include: An energy storage system body and a lithium battery capacity supplement device as claimed in any one of claims 1 to 6; The energy storage system body includes a BSC and at least one second battery unit; The BSC is communicatively connected with the second battery unit; When the number of the second battery units is greater than 1, each of the second battery units is connected to the external DC bus through a bus bar; When the capacity attenuation of the energy storage system body is greater than a preset attenuation threshold, at least one switch module in the lithium battery capacity supplement device is controlled to be turned on.

9. The energy storage system according to claim 8, characterized in that: The energy storage system body and the lithium battery capacity supplement device are arranged in the same cabinet.

10. The energy storage system according to claim 8, characterized in that: The energy storage system body and the lithium battery capacity supplement device are arranged in different cabinets.

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