An online upgrading method and system of a battery pack group and a battery management system

Abstract

The application belongs to the field of battery updating, and particularly relates to an online upgrading method and system of a battery pack group and a battery management system, the method comprising: obtaining the state of charge of each battery pack of a battery pack group to be upgraded; determining the battery pack to be upgraded and a discharging battery pack according to the state of charge; disconnecting the charging and discharging connection of the battery pack to be upgraded, upgrading the battery pack to be upgraded, and keeping the discharging battery pack to discharge externally; and after the upgrading of the battery pack to be upgraded is completed, upgrading the battery pack according to the real-time state of charge of the discharging battery pack. According to the state of charge of each battery pack of the battery pack group, the battery packs are classified, and the battery packs are upgraded in batches without affecting the normal power supply. The application guarantees the upgrading stability of the battery pack group, ensures the long-term normal working state of the battery pack group, improves the safety of the working of the battery pack group, and strengthens the user experience.

Description

Technical Field

[0001] This invention belongs to the field of battery upgrades, specifically relating to an online upgrade method, system, and battery management system for battery packs. Background Technology

[0002] With the increasing scale of distributed generation technology and renewable energy generation, energy storage systems are widely used in the market. Through rapid charging and discharging, energy storage systems can achieve dynamic adjustment of high power output, reducing the impact of external conditions on renewable energy generation systems and realizing the controllability of renewable power. The battery pack, as the most important component of the energy storage system, charges when there is no load and discharges when there is a load and power is scarce. However, upgrading the battery pack will cause it to stop charging and discharging. Therefore, the problem of how to ensure that the battery pack can still charge and discharge normally during upgrades urgently needs to be solved. Summary of the Invention

[0003] In view of the shortcomings of the prior art described above, the present invention provides a battery pack upgrade method, system and battery management system that can upgrade the battery pack without affecting the normal power supply to the outside.

[0004] To achieve the above and other related objectives, the present invention provides an online upgrade method for a battery pack, comprising:

[0005] Obtain the power status of each battery pack in the battery pack group to be upgraded;

[0006] Based on the stated battery status, determine the battery pack to be upgraded and the battery pack to be discharged;

[0007] Disconnect the charging and discharging connection of the battery pack to be upgraded, upgrade the battery pack to be upgraded, and keep the discharging battery pack discharging externally;

[0008] After the battery pack to be upgraded is completed, the battery pack upgrade is performed based on the real-time power status of the discharged battery pack.

[0009] In one embodiment of the present invention, the step of determining the battery pack to be upgraded and the battery pack to be discharged based on the state of charge includes:

[0010] The state of charge of each battery pack is evaluated according to a preset threshold.

[0011] Based on the stated battery status, determine whether the battery pack can be upgraded online:

[0012] If there is only a battery pack with any one of the following power states: low power, medium power, or high power, or if there is only a battery pack with low power and medium power and the proportion of the medium power battery pack is less than or equal to a preset proportion threshold, then the battery pack group is determined to be unable to be upgraded online.

[0013] Otherwise, it is determined that the battery pack can be upgraded online, and the battery pack to be upgraded and the battery pack to be discharged are determined according to the power status.

[0014] In one embodiment of the present invention, the step of determining the battery pack to be upgraded and the battery pack to be discharged based on the state of charge includes:

[0015] If the battery pack has a low power status and a medium power status, and the proportion of the medium power battery pack is greater than the proportion threshold, then the low power battery pack is designated as the battery pack to be upgraded, and the medium power battery pack is designated as the discharge battery pack.

[0016] If the battery pack's power status is low, medium, and high, or low and high, then the battery pack with low power is designated as the battery pack to be upgraded, and the remaining battery packs are designated as the discharge battery packs.

[0017] In one embodiment of the present invention, the step of determining the battery pack to be upgraded and the battery pack to be discharged based on the state of charge includes:

[0018] When only medium-capacity and high-capacity battery packs exist, the battery pack to be upgraded is determined based on the proportion of the medium-capacity battery pack, and the remaining battery packs are the discharge battery packs.

[0019] In one embodiment of the present invention, the step of determining the battery pack to be upgraded based on the proportion of battery packs with medium capacity, and the remaining battery packs being discharge battery packs, includes:

[0020] The proportion of the medium-capacity battery pack in the battery pack group is compared with a proportion threshold:

[0021] If the proportion of the battery pack with medium power is greater than the proportion threshold, then the battery pack with high power is designated as the battery pack to be upgraded, and the battery pack with medium power is designated as the battery pack to be discharged.

[0022] If the proportion of the battery pack with medium power is less than or equal to the proportion threshold, then the battery pack with medium power is designated as the battery pack to be upgraded, and the battery pack with high power is designated as the battery pack to be discharged.

[0023] In one embodiment of the present invention, before the step of upgrading the battery pack based on the real-time power status of the discharged battery pack after the upgrade of the battery pack is completed, the method further includes:

[0024] Determine whether the battery pack to be upgraded has been upgraded:

[0025] If the upgrade is complete, charge the upgraded battery pack until the battery pack reaches the preset power threshold.

[0026] If the upgrade is not completed, the battery pack to be upgraded will be upgraded again.

[0027] In one embodiment of the present invention, the step of upgrading the battery pack to be upgraded again if the upgrade is not completed includes:

[0028] If the upgrade is not completed, determine the number of upgrade attempts for the battery pack to be upgraded:

[0029] An alarm will be triggered when the number of upgrades to the battery pack to be upgraded exceeds or equals a preset upgrade count threshold.

[0030] When the number of upgrades for the battery pack to be upgraded is less than the preset upgrade number threshold, the upgrade is performed again.

[0031] In one embodiment of the present invention, after the battery pack to be upgraded is upgraded, the step of upgrading the battery pack based on the real-time power status of the discharged battery pack includes:

[0032] Obtain the real-time power status of the discharged battery pack;

[0033] Based on the real-time power status, the unupgraded discharge battery pack is converted into a battery pack to be upgraded and a discharge battery pack.

[0034] Disconnect the charging and discharging connection of the battery pack to be upgraded, upgrade the battery pack to be upgraded, discharge the battery pack and discharge the upgraded battery pack to the outside.

[0035] Repeat the above steps until all battery packs in the battery pack group have been upgraded.

[0036] To achieve the above and other related objectives, the present invention also provides an online upgrade system for a battery pack, comprising:

[0037] The power status acquisition module is used to acquire the power status of each battery pack in the battery pack group to be upgraded;

[0038] The determination module is used to determine the battery pack to be upgraded and the battery pack to be discharged based on the power status.

[0039] The upgrade module is used to disconnect the charging and discharging connection of the battery pack to be upgraded, upgrade the battery pack to be upgraded, and the discharging battery pack continues to discharge to the outside; the upgrade module is also used to upgrade the battery pack according to the real-time power status of the discharging battery pack after the battery pack to be upgraded is upgraded.

[0040] To achieve the above and other related objectives, the present invention also provides a battery management system applied to an energy storage system including a battery pack, wherein the battery management system performs online upgrades of the battery pack using any of the methods described herein.

[0041] The online upgrade method, system, and battery management system of this invention classify battery packs according to their respective power states and upgrade them in batches without affecting normal power supply. This invention ensures the stability of battery pack upgrades, guarantees the long-term normal operation of the battery pack, improves the safety of battery pack operation, and enhances the user experience. Attached Figure Description

[0042] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with the invention and, together with the description, serve to explain the principles of the invention. It is obvious that the drawings described below are merely some embodiments of the invention, and those skilled in the art can obtain other drawings based on these drawings without any inventive effort. In the drawings:

[0043] Figure 1 This is a detailed flowchart of an online upgrade method for a battery pack provided in an embodiment of the present invention;

[0044] Figure 2 This is a schematic diagram illustrating an application scenario of the battery pack provided in an embodiment of the present invention;

[0045] Figure 3 This is a functional block diagram of an online upgrade method for a battery pack provided in an embodiment of the present invention. Detailed Implementation

[0046] The following specific examples illustrate the implementation of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of the present invention.

[0047] Please see Figure 1-3 It should be noted that the illustrations provided in this embodiment are only schematic representations of the basic concept of the present invention. Therefore, the illustrations only show the components related to the present invention and are not drawn according to the actual number, shape and size of the components in the actual implementation. In the actual implementation, the form, quantity and proportion of each component can be arbitrarily changed, and the layout of the components may also be more complex.

[0048] Figure 1 A flowchart illustrating a preferred embodiment of the online upgrade method for the battery pack of the present invention is shown.

[0049] The following will combine Figure 1The online upgrade method for the battery pack in this embodiment will be described in detail, including:

[0050] Step S11: Obtain the power status of each battery pack in the battery pack group to be upgraded.

[0051] Specifically, in this embodiment, to achieve online upgrades of the battery pack, that is, to upgrade the battery pack while it is discharging normally, it is first necessary to obtain the State of Charge (SOC) of each battery pack in the battery pack to be upgraded.

[0052] Step S12: Based on the stated battery status, determine the battery pack to be upgraded and the battery pack to be discharged.

[0053] Based on the battery status, a portion of the battery packs can be selected as upgradeable battery packs, while the other portion can be used as discharge battery packs for external discharge.

[0054] In one specific embodiment, the step includes:

[0055] The state of charge of each battery pack is evaluated according to a preset threshold.

[0056] Based on the State of Charge (SOC) and preset threshold values ​​of each battery pack obtained in step S11, the battery packs are divided into low-capacity, medium-capacity, and high-capacity battery packs. In a preferred embodiment of the present invention, the fixed critical judgment criterion for setting the preset threshold values ​​is 40% for low-capacity and medium-capacity battery packs, and 70% for medium-capacity and high-capacity battery packs. That is, if the SOC of a battery pack is less than or equal to 40%, it is a low-capacity battery pack; if the SOC of a battery pack is greater than 40% and less than or equal to 70%, it is a medium-capacity battery pack; and if the SOC of a battery pack is greater than 70%, it is a high-capacity battery pack.

[0057] Based on the stated battery status, determine whether the battery pack can be upgraded online:

[0058] If there is only a battery pack with any one of the following power states: low power, medium power, or high power, or if there is only a battery pack with low power and medium power and the proportion of the medium power battery pack is less than or equal to a preset proportion threshold, then the battery pack group is determined to be unable to be upgraded online.

[0059] Otherwise, it is determined that the battery pack can be upgraded online, and the battery pack to be upgraded and the battery pack to be discharged are determined according to the power status.

[0060] Specifically, the State of Charge (SOC) of each battery pack obtained in step S11 is evaluated according to a preset threshold, and the battery packs are divided into low-charge, medium-charge, and high-charge battery packs. In a preferred embodiment of the present invention, if the SOC of a battery pack is less than or equal to 40%, it is a low-charge battery pack C; if the SOC of a battery pack is greater than 40% and less than or equal to 70%, it is a medium-charge battery pack B; and if the SOC of a battery pack is greater than 70%, it is a high-charge battery pack A.

[0061] Then, based on the different states of the battery packs within the battery pack group, it is determined whether online upgrades are possible: if the battery pack group consists entirely of battery packs C, B, or A, then the battery pack group cannot be upgraded online; if the battery pack group only contains battery packs C and B, the proportion of battery pack B in the battery pack group is calculated. When the proportion of battery pack B is less than or equal to a preset proportion threshold, the battery pack group also cannot be upgraded online; in other cases, the battery pack group is determined to be upgradable online; and the battery packs to be upgraded and the battery packs to be discharged are determined according to different situations. The proportion threshold is set based on the number of normally functioning battery packs. For example, in a specific embodiment of the present invention, when the number of normally functioning battery packs is less than or equal to 2, the battery pack group cannot be upgraded online, and the proportion threshold is ineffective; when the number of normally functioning battery packs is greater than 2 but less than or equal to 4, the proportion threshold is set to 60%; when the number of normally functioning battery packs is greater than 4, the proportion threshold is set to 50%.

[0062] In one embodiment, the step further includes: if the battery pack's power state is low and medium and the proportion of medium-power battery packs is greater than the proportion threshold, then the low-power battery pack is designated as the battery pack to be upgraded, and the medium-power battery pack is designated as the discharge battery pack; if the battery pack's power state is low, medium, and high, or low and high, then the low-power battery pack is designated as the battery pack to be upgraded, and the remaining battery packs are designated as the discharge battery packs.

[0063] In one embodiment, the step further includes: when only medium-capacity and high-capacity battery packs exist, determining the battery pack to be upgraded based on the proportion of the medium-capacity battery packs, and the remaining battery packs being the discharge battery packs.

[0064] In one embodiment, the step of determining the battery pack to be upgraded based on the proportion of the battery pack with medium capacity, and the remaining battery packs as discharge battery packs, includes: comparing the proportion of the battery pack with medium capacity in the battery pack group with a proportion threshold; if the proportion of the battery pack with medium capacity is greater than the proportion threshold, then the battery pack with high capacity is designated as the battery pack to be upgraded, and the battery pack with medium capacity is designated as the discharge battery pack; if the proportion of the battery pack with medium capacity is less than or equal to the proportion threshold, then the battery pack with medium capacity is designated as the battery pack to be upgraded, and the battery pack with high capacity is designated as the discharge battery pack.

[0065] Specifically, when battery pack C, battery pack B, and battery pack A are all present in the battery pack group, battery pack C is designated as the battery pack to be upgraded, and battery packs B and A are designated as discharge battery packs; when only battery pack C and battery pack A are present in the battery pack group, battery pack C is designated as the battery pack to be upgraded, and battery pack A is designated as the discharge battery pack; when only battery pack C and battery pack B are present in the battery pack group, but the proportion of battery pack B is greater than a preset proportion threshold, then battery pack C is designated as the battery pack to be upgraded, and battery pack B is designated as the discharge battery pack; when only battery pack B and battery pack A are present in the battery pack group, if the proportion of battery pack B is less than or equal to the proportion threshold, then battery pack B is designated as the battery pack to be upgraded, and battery pack A is designated as the discharge battery pack; conversely, if the proportion of battery pack B is greater than the proportion threshold, then battery pack A is designated as the battery pack to be upgraded, and battery pack B is designated as the discharge battery pack.

[0066] Step S13: Disconnect the charging and discharging connection of the battery pack to be upgraded, upgrade the battery pack to be upgraded, and keep the discharging battery pack discharging externally.

[0067] Specifically, after identifying the battery pack to be upgraded, the charging and discharging connection of the battery pack to be upgraded is disconnected and the first upgrade is performed; at the same time, the discharging battery pack is kept in normal charging and discharging mode.

[0068] Step S14: After the battery pack to be upgraded is completed, the battery pack is upgraded according to the real-time power status of the discharged battery pack.

[0069] In one embodiment, the method further includes, before this step, determining whether the battery pack to be upgraded has been upgraded: if the upgrade is completed, charging the upgraded battery pack until the power state of the upgraded battery pack reaches a preset power threshold; if the upgrade is not completed, upgrading the battery pack to be upgraded again.

[0070] In one embodiment, the step of upgrading the battery pack to be upgraded again if the upgrade is not completed includes: if the upgrade is not completed, determining the number of upgrades of the battery pack to be upgraded: when the number of upgrades of the battery pack to be upgraded is greater than or equal to a preset upgrade number threshold, issuing an alarm; when the number of upgrades of the battery pack to be upgraded is less than the preset upgrade number threshold, upgrading again.

[0071] Specifically, after the first upgrade, it is necessary to determine whether the battery pack was successfully upgraded. If the upgrade is successful, the battery pack to be upgraded and the battery pack to be discharged for the second upgrade are determined simultaneously, and the battery pack that was upgraded in the first upgrade is charged until its SOC reaches the preset power threshold. For battery packs that failed to upgrade, their upgrade attempts are accumulated. When a battery pack fails to upgrade, the number of upgrade attempts for that battery pack is first determined. If the number of upgrade attempts is less than the preset upgrade attempt threshold, the battery pack to be upgraded is upgraded again; if the number of upgrade attempts is greater than or equal to the preset upgrade attempt threshold, an alarm is triggered.

[0072] In this embodiment, when the upgraded battery pack is battery pack C, it is charged until it reaches the SOC of battery pack B and then switched to the discharge state; when the upgraded battery pack is battery pack B, it is charged until it reaches the SOC of battery pack A and then switched to the discharge state; when the upgraded battery pack is battery pack A, it directly enters the discharge state.

[0073] In one embodiment, the step includes: acquiring the real-time power status of the discharge battery pack; converting the unupgraded discharge battery pack into a battery pack to be upgraded and a discharge battery pack based on the real-time power status; disconnecting the charging and discharging connection of the battery pack to be upgraded, upgrading the battery pack to be upgraded, discharging the battery pack, and discharging the upgraded battery pack to the outside; repeating the above steps until all battery packs in the battery pack group have been upgraded.

[0074] Specifically, after all battery packs to be upgraded are completed, the State of Charge (SOC) of the discharged battery packs is updated. All un-upgraded battery packs (i.e., un-upgraded discharged battery packs) are then categorized based on their different charge levels to determine the battery packs to be upgraded and the discharged battery packs. The charging and discharging connections of the battery packs to be upgraded are then disconnected, and the upgrade is performed. The discharged battery packs and the upgraded battery packs remain discharged. After the battery packs to be upgraded are completed, the above steps are repeated until all battery packs in the battery pack group have been upgraded.

[0075] It should be noted that the steps of the various methods described above are only for clarity. In practice, they can be combined into one step or some steps can be split into multiple steps. As long as they contain the same logical relationship, they are all within the protection scope of this invention. Adding insignificant modifications or introducing insignificant designs to the algorithm or process, without changing the core design of the algorithm and process, are also within the protection scope of this invention.

[0076] like Figure 3 The diagram shown is a functional block diagram of a preferred embodiment of the online upgrade system for the battery pack of the present invention. The online upgrade system for the battery pack includes: a power status acquisition module 31, a determination module 32, and an upgrade module 33;

[0077] The power status acquisition module 31 is used to acquire the power status of each battery pack in the battery pack group to be upgraded.

[0078] The determining module 32 is used to determine the battery pack to be upgraded and the battery pack to be discharged based on the power status.

[0079] The upgrade module 33 is used to disconnect the charging and discharging connection of the battery pack to be upgraded, upgrade the battery pack to be upgraded, and the discharging battery pack continues to discharge to the outside; the upgrade module 33 is also used to upgrade the battery pack according to the real-time power status of the discharging battery pack after the battery pack to be upgraded is completed.

[0080] It should be noted that the online upgrade system for the battery pack in this embodiment corresponds to the online upgrade method for the battery pack described above. The functional modules in the online upgrade system for the battery pack may correspond to specific steps in the online upgrade method for the battery pack. The online upgrade system for the battery pack in this embodiment can be implemented in conjunction with the online upgrade method for the battery pack. Accordingly, the relevant technical details mentioned in the online upgrade system for the battery pack in this embodiment can also be applied to the online upgrade method for the battery pack described above.

[0081] It should be noted that the aforementioned functional modules can be fully or partially integrated into a single physical entity, or they can be physically separated. Furthermore, these modules can be implemented entirely in software via processing element calls; they can be implemented entirely in hardware; or some modules can be implemented by processing element calls to software, while others are implemented in hardware. Additionally, these modules can be fully or partially integrated together, or they can be implemented independently.

[0082] This embodiment also discloses a battery management system (BMS) applied to an energy storage system comprising multiple battery packs. For example... Figure 2As shown, the energy storage system includes, but is not limited to, multiple battery packs, multiple DC / DC transformers, and AC / DC converters. Each battery pack is connected in series with its corresponding DC transformer, and then connected to the AC / DC converter, which is connected to the power grid or a load. When the battery packs of the energy storage system need to be charged, the AC / DC converter converts AC power to DC power, and the DC power is then converted into charging current for the corresponding battery pack through the DC transformer. When the battery packs of the energy storage system need to discharge, the battery packs convert AC power back to AC power through the corresponding DC transformer and the AC / DC converter to supply power to the load.

[0083] The battery management system (BMS) employs the online upgrade method described above to upgrade multiple battery packs within the energy storage system. Furthermore, the BMS can collect real-time data on the battery pack's operating status (including but not limited to State of Charge (SOC), temperature, health status, charge / discharge voltage / current, etc.) and adjust the operating parameters of the DC-DC converter and AC-DC converter based on the external power grid and load conditions.

[0084] In summary, the online upgrade method, system, and battery management system of the present invention classify the battery packs according to their respective power states and upgrade them in batches without affecting normal power supply. This invention ensures the stability of the battery pack upgrade, guarantees the long-term normal operation of the battery pack, improves the safety of battery pack operation, and enhances the user experience. Compared with existing technologies, it produces unexpected technical effects.

[0085] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the present invention can be implemented in other specific forms without departing from the spirit or essential characteristics of the present invention.

[0086] The above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention.

Claims

1. An online upgrade method for a battery pack, characterized in that, include: The power status of each battery pack in the battery pack is monitored in real time during the normal discharge process of the battery pack; Based on the state of charge of each battery pack, determine the battery pack to be upgraded and the battery pack to be discharged, including: evaluating the state of charge of each battery pack according to a preset threshold, and determining whether the battery pack group can be upgraded online: if there are only battery packs with any one of the following state of charge: low, medium or high, or only low and medium battery packs, and the proportion of medium battery packs is less than or equal to a preset proportion threshold, then the battery pack group is determined not to be upgraded online; otherwise, the battery pack group is determined to be upgradeable online, and the battery pack to be upgraded and the battery pack to be discharged are determined based on the state of charge of each battery pack. Disconnect the charging and discharging connection of the battery pack to be upgraded in order to upgrade the battery pack, while maintaining the discharge of the battery pack to discharge externally; After the battery pack to be upgraded is completed, the battery pack upgrade is performed based on the real-time power status of the discharged battery pack.

2. The online upgrade method for a battery pack according to claim 1, characterized in that, The step of determining the battery pack to be upgraded and the battery pack to be discharged based on the power status of each battery pack includes: If the battery pack has a low power status and a medium power status, and the proportion of the medium power battery pack is greater than the proportion threshold, then the low power battery pack is designated as the battery pack to be upgraded, and the medium power battery pack is designated as the discharge battery pack. If the battery pack's power status is low, medium, and high, or low and high, then the battery pack with low power is designated as the battery pack to be upgraded, and the remaining battery packs are designated as the discharge battery packs.

3. The online upgrade method for a battery pack according to claim 1, characterized in that, The step of determining the battery pack to be upgraded and the battery pack to be discharged based on the power status of each battery pack includes: When only medium-capacity and high-capacity battery packs exist, the battery pack to be upgraded is determined based on the proportion of the medium-capacity battery pack, and the remaining battery packs are the discharge battery packs.

4. The online upgrade method for the battery pack according to claim 3, characterized in that, The step of determining the battery packs to be upgraded based on the proportion of battery packs with medium charge, and the remaining battery packs being discharge battery packs, includes: The proportion of the medium-capacity battery pack in the battery pack group is compared with a proportion threshold: If the proportion of the battery pack with medium power is greater than the proportion threshold, then the battery pack with high power is designated as the battery pack to be upgraded, and the battery pack with medium power is designated as the battery pack to be discharged. If the proportion of the battery pack with medium power is less than or equal to the proportion threshold, then the battery pack with medium power is designated as the battery pack to be upgraded, and the battery pack with high power is designated as the battery pack to be discharged.

5. The online upgrade method for a battery pack according to claim 1, characterized in that, Before the step of upgrading the battery pack based on its real-time power status after the upgrade of the battery pack to be upgraded is completed, the following steps are also included: Determine whether the battery pack to be upgraded has been upgraded: If the upgrade is complete, charge the upgraded battery pack until the battery pack reaches the preset power threshold. If the upgrade is not completed, the battery pack to be upgraded will be upgraded again.

6. The online upgrade method for a battery pack according to claim 5, characterized in that, The step of upgrading the battery pack again if the upgrade is not completed includes: If the upgrade is not completed, determine the number of upgrade attempts for the battery pack to be upgraded: An alarm will be triggered when the number of upgrades to the battery pack to be upgraded exceeds or equals a preset upgrade count threshold. When the number of upgrades for the battery pack to be upgraded is less than the preset upgrade number threshold, the upgrade is performed again.

7. The online upgrade method for a battery pack according to claim 5, characterized in that, The steps for upgrading the battery pack after the upgrade is completed, based on the real-time power status of the discharged battery pack, include: Obtain the real-time power status of the discharged battery pack; Based on the real-time power status, the unupgraded discharge battery pack is converted into a battery pack to be upgraded and a discharge battery pack. Disconnect the charging and discharging connection of the battery pack to be upgraded, upgrade the battery pack to be upgraded, discharge the battery pack and discharge the upgraded battery pack to the outside. Repeat the above steps until all battery packs in the battery pack group have been upgraded.

8. An online upgrade system for a battery pack, characterized in that, include: The power status acquisition module is used to monitor the power status of each battery pack in the battery pack in real time during the normal discharge process of the battery pack. The determination module is used to determine the battery pack to be upgraded and the discharging battery pack based on the power status of each battery pack. This includes: evaluating the power status of each battery pack according to a preset threshold, and determining whether the battery pack group can be upgraded online: if only battery packs with any one of low, medium, or high power status exist, or only low and medium power battery packs exist and the proportion of medium power battery packs is less than or equal to a preset proportion threshold, then the battery pack group is determined not to be upgraded online; otherwise, the battery pack group is determined to be upgradeable online, and the battery pack to be upgraded and the discharging battery pack are determined based on the power status of each battery pack. The upgrade module is used to disconnect the charging and discharging connection of the battery pack to be upgraded in order to upgrade the battery pack to be upgraded, and to maintain the discharge of the discharge battery pack to the outside; the upgrade module is also used to upgrade the battery pack according to the real-time power status of the discharge battery pack after waiting for the upgrade of the battery pack to be upgraded to be completed.

9. A battery management system, characterized in that, Applied to an energy storage system including a battery pack, the battery management system performs online upgrades of the battery pack using the method described in any one of claims 1 to 7.

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