Multi-battery pack management methods and energy storage devices

Abstract

This application provides a multi-battery pack management method and energy storage device, relating to the field of battery technology. The method includes: obtaining the current parallel voltage range corresponding to all currently active battery packs; determining a switching voltage threshold based on the current parallel voltage range; determining a first extreme voltage corresponding to all currently active battery packs and a second extreme voltage corresponding to all currently inactive battery packs based on the current state of the parallel system and the battery voltages of the multiple battery packs; and performing a battery pack switching operation when the voltage difference between the first extreme voltage and the second extreme voltage is greater than the switching voltage threshold. The battery pack switching operation includes configuring all currently active battery packs as inactive and configuring the battery pack corresponding to the second extreme voltage as active. This application allows battery packs to participate in charging and discharging as soon as possible after being connected, avoiding prolonged inactivity.

Description

Technical Field

[0001] This application relates to the field of battery technology, and in particular to multi-battery pack management methods and energy storage devices. Background Technology

[0002] In energy storage devices, multiple battery packs are connected to the same charging / discharging port via a parallel port, which is called parallel operation. During parallel operation, multiple battery packs are controlled by the same controller, which determines which battery packs are enabled or disabled to ensure charging and discharging safety.

[0003] When a battery pack is added or removed, or when the voltage between battery packs changes, operations such as battery pack switching, parallel operation, and decommissioning may be required. For example, switching from parallel discharge of battery packs A and B to discharge of battery pack C (switching operation); or enabling battery pack C to discharge in parallel while battery packs A and B are discharging (parallel operation) to allow battery packs A, B, and C to discharge in parallel; or disabling battery pack B to discharge only battery pack A while battery packs A and B are discharging in parallel (decommissioning operation). These operations are typically determined by the voltage difference between the battery packs. In multi-battery pack control schemes, it is common to encounter situations where, after a new battery pack is added, parallel operation or switching operations cannot be performed, requiring a long waiting time.

[0004] Therefore, in multi-battery pack control schemes, ensuring that the connected battery packs can be used quickly is an urgent problem to be solved. Summary of the Invention

[0005] To address the aforementioned technical problems, embodiments of this application provide a multi-battery pack management method and an energy storage device.

[0006] In a first aspect, embodiments of this application provide a multi-battery pack management method applied to a controller, wherein the controller is connected to multiple battery packs, the multiple battery packs forming a parallel system, and the multi-battery pack management method includes:

[0007] Get the current parallel voltage range for all currently active battery packs;

[0008] Determine the switching voltage threshold based on the current parallel voltage range;

[0009] Based on the current state of the parallel system and the battery voltages of the multiple battery packs, determine the first extreme voltage corresponding to all currently activated battery packs and the second extreme voltage corresponding to all currently inactive battery packs;

[0010] When the voltage difference between the first extreme voltage and the second extreme voltage is greater than the switching voltage threshold, a battery pack switching operation is performed; the battery pack switching operation includes configuring all currently enabled battery packs to be disabled and configuring the battery pack corresponding to the second extreme voltage to be enabled.

[0011] In one embodiment, determining a first extreme voltage corresponding to all currently active battery packs and a second extreme voltage corresponding to all currently inactive battery packs based on the current state of the parallel system and the battery voltages of the plurality of battery packs includes:

[0012] In the charging state, the minimum battery voltage among all currently activated battery packs is determined as the first extreme voltage, and the minimum battery voltage among all currently inactive battery packs is determined as the second extreme voltage; or,

[0013] In the discharge state, the maximum battery voltage among all currently activated battery packs is determined as the first extreme voltage, and the maximum battery voltage among all currently inactive battery packs is determined as the second extreme voltage.

[0014] In one embodiment, determining the switching voltage threshold based on the current parallel voltage range includes:

[0015] Obtain the upper and lower limits of the current parallel voltage range;

[0016] The difference between the upper limit value and the lower limit value is used to obtain the switching voltage threshold.

[0017] In one embodiment, the method further includes:

[0018] The battery pack corresponding to the first extreme voltage is determined as the reference battery pack;

[0019] The current parallel voltage range is determined based on the battery voltage of the reference battery pack, the current of the reference battery pack, and the preset correlation between the current and the parallel voltage difference range.

[0020] In one embodiment, the method further includes:

[0021] When any of the battery packs currently not enabled meets the parallel operation conditions, the battery pack that meets the parallel operation conditions will be configured to be enabled; the parallel operation conditions are: the battery voltage falls within the current parallel operation voltage range.

[0022] In one embodiment, the method further includes:

[0023] If any of the currently enabled battery packs does not meet the parallel operation conditions, the battery pack that does not meet the parallel operation conditions will be configured to be disabled; the parallel operation conditions are: the battery voltage of the battery pack does not fall within the current parallel operation voltage range.

[0024] In one embodiment, the method further includes:

[0025] When all currently enabled battery packs change, update the first extreme voltage and determine the new reference battery pack;

[0026] When the reference battery pack changes, the current parallel voltage range is updated.

[0027] In one embodiment, determining the battery pack corresponding to the first extreme voltage as the reference battery pack includes:

[0028] In the charging state, the battery pack with the highest battery voltage among all currently activated battery packs is determined as the reference battery pack; or,

[0029] In the discharge state, the battery pack with the lowest battery voltage among all currently activated battery packs is determined as the reference battery pack.

[0030] In one embodiment, the method further includes: acquiring battery pack data for each battery pack, the battery pack data including: battery voltage, current and error code for each battery pack;

[0031] When no battery pack is currently in use, the target battery pack is determined based on all the battery pack data.

[0032] Configure the target battery pack to be enabled.

[0033] In one embodiment, the error code is used to identify whether there is an error in the battery pack;

[0034] The step of determining the target battery pack based on all the battery pack data includes:

[0035] During charging, the battery pack with no errors and the lowest battery voltage is identified as the target battery pack; or,

[0036] In the discharge state, the battery pack with no errors and the highest battery voltage is identified as the target battery pack.

[0037] Secondly, embodiments of this application provide an energy storage device, which includes a parallel port, a controller, a memory, and a battery pack;

[0038] The parallel port is used to connect with other energy storage devices;

[0039] The controller is connected to each battery pack;

[0040] The memory stores computer-readable instructions, which, when executed by the controller, implement the multi-battery pack management method as described above.

[0041] Thirdly, embodiments of this application provide an energy storage system, including at least two energy storage devices connected through a parallel port, wherein at least one of the energy storage devices is the energy storage device described above.

[0042] Fourthly, embodiments of this application provide a computer-readable storage medium that stores computer instructions that, when executed on an electronic device, cause the electronic device to perform the multi-battery pack management method as described in any of the preceding claims.

[0043] The multi-battery pack management method and energy storage device provided in this application determine a switching voltage threshold based on the current parallel voltage range. Based on the state of the parallel system and the battery voltages of all battery packs, it determines a first extreme voltage corresponding to the activated battery pack and a second extreme voltage corresponding to the inactive battery pack. When the voltage difference between the two extreme voltages exceeds the switching voltage threshold, a battery pack switching operation is performed. In other words, this application dynamically adjusts the switching voltage threshold according to changes in the current parallel voltage range, rather than using a simple fixed threshold. This allows for faster switching if, after a battery pack is connected, parallel operation is not possible based on the current parallel voltage range. This ensures that the battery pack can participate in charging and discharging promptly after connection, avoiding prolonged waiting and achieving flexible switching operations. Attached Figure Description

[0044] To more clearly illustrate the technical solutions in this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort. In the drawings:

[0045] Figure 1 This is a schematic diagram of one implementation environment involved in this application;

[0046] Figure 2 This is a first flowchart illustrating a multi-battery pack management method in an exemplary embodiment of this application;

[0047] Figure 3 This is a second flowchart illustrating a multi-battery pack management method in another exemplary embodiment of this application;

[0048] Figure 4 This is a schematic diagram of parallel operation under charging and discharging conditions in related technologies;

[0049] Figure 5 This is a third flowchart illustrating a multi-battery pack management method in another exemplary embodiment of this application;

[0050] Figure 6This is a schematic diagram of parallel operation under charging and discharging conditions in this application;

[0051] Figure 7 This is a fourth flowchart illustrating a multi-battery pack management method according to another exemplary embodiment of this application;

[0052] Figure 8 This is a fifth flowchart illustrating a multi-battery pack management method in another exemplary embodiment of this application;

[0053] Figure 9 This is a sixth flowchart illustrating a multi-battery pack management method in another exemplary embodiment of this application;

[0054] Figure 10 This is a seventh flowchart illustrating a multi-battery pack management method in another exemplary embodiment of this application;

[0055] Figure 11 This is a structural schematic diagram of the energy storage device of this application;

[0056] Figure 12 This is a schematic diagram of the energy storage system of this application. Detailed Implementation

[0057] To make the objectives, technical solutions, and advantages of this application clearer, the technical solutions of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0058] The block diagrams shown in the accompanying drawings are merely functional entities and do not necessarily correspond to physically independent entities. That is, these functional entities can be implemented in software, in one or more hardware modules or integrated circuits, or in different network and / or processor devices and / or microcontroller devices.

[0059] The flowcharts shown in the accompanying drawings are merely illustrative and do not necessarily include all content and operations / steps, nor do they necessarily have to be performed in the described order. For example, some operations / steps can be broken down, while others can be combined or partially combined; therefore, the actual execution order may change depending on the specific circumstances.

[0060] It should be noted that in this application, "at least one" means one or more, and "more than one" means two or more. "And / or" describes the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A alone, A and B simultaneously, or B alone, where A and B can be singular or plural. The terms "first," "second," "third," "fourth," etc. (if present) in the specification, claims, and drawings of this application are used to distinguish similar objects, not to describe a specific order or sequence.

[0061] See Figure 1 , Figure 1 This is a schematic diagram of an implementation environment related to this application. The implementation environment includes a controller 1120, a parallel system 1150, and a power conversion device 1170.

[0062] The parallel system 1150 includes multiple battery packs 1140 and charging / discharging ports 1160, for example, Figure 1 The first and second battery packs are shown. The controller 1120 is connected to each battery pack in the parallel system 1150 and is used to uniformly control the multiple battery packs in the parallel system 1150, determining which battery packs are enabled or disabled.

[0063] Multiple battery packs 1140 are all connected to the same charging / discharging port 1160. A parallel system 1150 is connected to a power conversion device 1170 via the charging / discharging port 1160. Each battery pack in the parallel system 1150 discharges or receives charge through the power conversion device 1170. For example, the controller 1120 determines which battery packs are enabled and can discharge or receive charge through the power conversion device 1170, and determines which battery packs are disabled and cannot discharge or receive charge. For instance, if the controller 1120 enables the first battery pack and disables the second battery pack, then the first battery pack can discharge or receive charge through the inverter, while the second battery pack cannot discharge or receive charge.

[0064] In some embodiments, the power conversion device 1170 may integrate various types of power conversion circuits, including but not limited to DC / DC circuits such as buck-boost circuits, maximum power point tracking (MPPT) circuits, and AC / DC circuits such as inverter circuits and rectifier circuits. This application does not limit the internal circuit composition of the power conversion device 1170.

[0065] In some embodiments, controller 1120 may be a controller integrated within any battery pack in the parallel system 1150. For example, controller 1120 may be a controller within the main battery pack. After all battery packs are connected to form the parallel system 1150, the main battery pack and slave battery packs can be determined from the connected battery packs based on preset arbitration rules. The controller of the main battery pack can then act as the management system (Energy Management System, EMS) of the parallel system 1150, managing each battery pack within the parallel system 1150. The preset arbitration rules can be set according to specific circumstances, and this application does not impose specific limitations.

[0066] In some embodiments, controller 1120 may also be a separate controller existing outside parallel system 1150 for controlling all battery packs in parallel system 1150.

[0067] It is understood that in some embodiments, the parallel system may also consist of an energy storage device and multiple independent battery packs or multiple other energy storage devices. In this case, the energy storage device includes a parallel port, which can be connected with other energy storage devices and / or battery packs to form a parallel system. All energy storage devices and / or battery packs in the parallel system can discharge or receive charging through the charging or discharging interface of one of the energy storage devices.

[0068] Practical applications confirm that when multiple battery packs are used in parallel for charging or discharging, to avoid excessive voltage differences between the packs leading to mutual charging, the voltage difference between the activated battery packs should be maintained within a certain range, i.e., the parallel voltage difference range. The permissible parallel voltage difference range is also related to the charging and discharging current of the battery packs. When considering the parallel voltage difference range, a reference battery pack is usually selected. Whether other battery packs should be added depends on whether their voltage difference with the reference battery pack meets the parallel voltage difference range. When a new battery pack is added, a battery pack switching operation may be required, i.e., enabling the newly added battery pack and deactivating the currently enabled battery pack.

[0069] In related technologies, determining whether a battery pack switching operation needs to be performed typically involves first calculating the switching voltage threshold based on the sum of the upper and lower absolute values ​​of the maximum parallel voltage difference range. In this case, the calculated switching voltage threshold is a fixed value, independent of the currently active battery pack and the current parallel voltage range. If this switching voltage threshold is set improperly, it can easily lead to the newly added battery pack being unable to be used for an extended period.

[0070] Table 1 Correspondence between current and parallel voltage difference range

[0071]

[0072]

[0073] For example, Table 1 is a correspondence table of current and parallel voltage difference range. As shown in Table 1, the maximum parallel voltage difference range is (-100mV, +1488mV), meaning the switching voltage threshold is 1.588V. In Table 1, a current greater than or equal to 1A indicates the battery pack is charging, and a current less than 1A indicates the battery pack is discharging or in standby mode. When a new battery pack is connected, the voltage difference between the newly connected battery pack and the reference battery pack is detected to determine whether to perform a battery pack switching operation. For example, if the voltage difference between the newly connected battery pack and the reference battery pack is greater than the switching voltage threshold, the controller 1120 performs a battery pack switching operation, making the newly connected battery pack the enabled battery pack and disabling all previously enabled battery packs. If the voltage difference between the newly connected battery pack and the reference battery pack is less than the switching voltage threshold, the controller 1120 does not perform a battery pack switching operation.

[0074] When the battery pack is charging or discharging, the voltage difference between the battery voltage of the newly connected battery pack and the battery voltage of the reference battery pack may not reach the switching voltage threshold. In this case, the newly connected battery pack needs to wait for a certain period of time, and the reference battery pack needs to discharge or charge for a certain period of time so that the voltage difference between the newly connected battery pack and the reference battery pack reaches the switching voltage threshold before the controller 1120 performs the battery pack switching operation.

[0075] For example, if the first and second battery packs are already in parallel operation, with the second battery pack serving as a reference pack, and the voltage of a newly added third battery pack just exceeds the parallel operation voltage range, then the third battery pack is not eligible for parallel operation. If the voltage of the third battery pack is higher than that of the second battery pack, but the voltage difference between them does not reach the switching voltage threshold, then the third battery pack also cannot perform a switching operation. The third battery pack needs to wait for the second battery pack to continue discharging until the voltage difference between them reaches the switching voltage threshold.

[0076] However, for battery packs, if the battery pack voltage is not high and / or the charging and discharging current is not high, the second battery pack may need to discharge or charge for a long time before the voltage difference between it and the third battery pack can reach the switching voltage threshold of 1.588V. In this case, after the third battery pack is connected, it will take a long time before it can be used normally, which cannot meet the user's expectations.

[0077] To address the aforementioned issues, this application provides a multi-battery pack management method. By dynamically adjusting the switching voltage threshold according to changes in the current parallel voltage range, rather than using a simple fixed threshold, the method ensures that if the parallel voltage range is not met after the battery pack is connected, the switching voltage threshold can be met. This ensures that the battery pack can participate in charging and discharging promptly after being connected, avoiding long waiting times and enabling flexible switching operations.

[0078] Figure 2 This is a first flowchart illustrating a multi-battery pack management method in an exemplary embodiment of this application, as shown below. Figure 2 As shown in an exemplary embodiment, the multi-battery pack management method includes steps 210 to 240, which are described in detail below.

[0079] Step 210: Obtain the current parallel voltage range for all currently enabled battery packs.

[0080] Specifically, at the current moment, depending on whether the battery pack in the parallel system 1150 is configured to be enabled by the controller 1120, the battery pack in the parallel system 1150 can be divided into currently enabled battery packs and currently disabled battery packs.

[0081] For example, the parallel system 1150 includes a first battery pack, a second battery pack, and a third battery pack. The first and second battery packs are configured to be enabled by the controller 1120, and the third battery pack is configured to be disabled by the controller 1120. In this case, the first and second battery packs are both currently enabled, and the third battery pack is currently disabled.

[0082] The set of all currently active battery packs is defined as the collection of all currently active battery packs. For example, the set of all currently active battery packs is defined as the collection of the first battery pack and the second battery pack.

[0083] The controller 1120 can first determine all currently active battery packs in the parallel system 1150, and then obtain the current parallel voltage range based on all currently active battery packs.

[0084] The current parallel voltage range corresponds to all currently enabled battery packs. When the number of currently enabled battery packs changes, for example, if a new battery pack is added that meets the parallel voltage range and is enabled, or if one of the currently enabled battery packs is disabled, the controller 1120 re-acquires the current parallel voltage range based on the changed list of currently enabled battery packs.

[0085] It is understandable that the current parallel voltage range depends on all currently active battery packs, including their battery voltages and charging / discharging currents. Once the active battery packs are determined, the current parallel voltage range can be determined based on a preset mapping relationship. For example, a reference voltage can be determined from the battery voltages of all currently active battery packs. By referring to Table 1 with the corresponding charging / discharging currents, the voltage difference range can be determined, thus obtaining the current parallel voltage range.

[0086] Step 220: Determine the switching voltage threshold based on the current parallel voltage range.

[0087] Specifically, the switching voltage threshold is determined by the current parallel voltage range, so that the switching voltage threshold can be dynamically adjusted as the current parallel voltage range changes. The larger the current parallel voltage range, the larger the switching voltage threshold.

[0088] In some embodiments, the controller 1120 may preset a correspondence between the parallel voltage range and the switching voltage threshold, so that the controller 1120 determines the switching voltage threshold corresponding to the current parallel voltage range based on the current parallel voltage range and the correspondence.

[0089] Step 230: Based on the current state of the parallel system 1150 and the battery voltages of the multiple battery packs, determine the first extreme voltage corresponding to all currently activated battery packs and the second extreme voltage corresponding to all currently inactive battery packs.

[0090] Specifically, the multiple battery packs include all currently active battery packs and all currently inactive battery packs; that is, the battery voltage of the multiple battery packs includes the battery voltage of all battery packs in the parallel system.

[0091] Based on the current state of the parallel system 1150, a first extreme voltage is determined from the battery voltages of all currently active battery packs, and a second extreme voltage is determined from the battery voltages of all currently inactive battery packs.

[0092] The current state of the parallel system 1150 can include a charging state and a discharging state, and the extreme voltage can be the voltage with the highest voltage value or the voltage with the lowest voltage value. The controller 1120 can preset the correspondence between the current state of the parallel system 1150 and the extreme voltage, so as to determine whether the first extreme voltage and the second extreme voltage are the voltage with the highest voltage value or the voltage with the lowest voltage value according to the current state of the parallel system 1150.

[0093] For example, during charging, the minimum battery voltage among all currently active battery packs is determined as the first extreme voltage, and the minimum battery voltage among all currently inactive battery packs is determined as the second extreme voltage.

[0094] The charging principle is to prioritize charging battery packs with lower battery voltages. Therefore, if there is a battery pack in the inactive group with a lower battery voltage than any of the currently active battery packs, a switching operation is required.

[0095] Therefore, when the current state of the parallel system 1150 is the charging state, the minimum battery voltage among all currently activated battery packs is determined as the first extreme voltage, and the minimum battery voltage among all currently inactive battery packs is determined as the second extreme voltage. This makes it easy to determine whether a switching operation is needed by comparing the first extreme voltage and the second extreme voltage.

[0096] For example, in a discharge state, the maximum battery voltage among all currently active battery packs is determined as the first extreme voltage, and the maximum battery voltage among all currently inactive battery packs is determined as the second extreme voltage.

[0097] The basic principle of discharge is to prioritize the discharge of battery packs with higher battery voltages. Therefore, if there is a battery pack in the unused battery packs with a higher battery voltage than any of the currently used battery packs, a switching operation is required.

[0098] Therefore, when the current state of the parallel system 1150 is the discharge state, the maximum battery voltage among all currently activated battery packs is determined as the first extreme voltage, and the maximum battery voltage among all currently inactive battery packs is determined as the second extreme voltage. This makes it easier to determine whether a switching operation is needed by comparing the first extreme voltage and the second extreme voltage.

[0099] Step 240: If the voltage difference between the first extreme voltage and the second extreme voltage is greater than the switching voltage threshold, perform a battery pack switching operation; the battery pack switching operation includes configuring all currently enabled battery packs to be disabled and configuring the battery pack corresponding to the second extreme voltage to be enabled.

[0100] Specifically, if the voltage difference between the first extreme voltage and the second extreme voltage is greater than the switching voltage threshold, it indicates that there are battery packs with lower voltage (charging state) or higher voltage among the currently inactive battery packs. Based on the basic principles of charging and discharging, these battery packs should be charged or discharged first. Therefore, when the voltage difference between the first extreme voltage and the second extreme voltage is greater than the switching voltage threshold, the controller 1120 performs a battery pack switching operation. That is, the controller 1120 configures all currently active battery packs to be inactive and configures the battery pack corresponding to the second extreme voltage to be active.

[0101] To facilitate understanding, the multi-battery pack management method of this embodiment will be illustrated with specific examples below:

[0102] The parallel system 1150 is currently charging. The first battery pack is currently in use, with a battery voltage of 54.4V. The second and third battery packs are not in use. The second battery pack has a battery voltage of 54V, and the third battery pack has a battery voltage of 54.1V.

[0103] By adopting the technical solution of this application, the corresponding voltage difference range can be determined as [-264mV, +100mV] based on the query of the currently activated first battery pack. Therefore, the current parallel voltage range is [54.4V-0.264V, 54.4V+0.100V]. If the switching voltage threshold is set to a fixed value according to related technologies, considering the need to adapt to all situations, this threshold usually needs to be set relatively large, such as the aforementioned 1.588V. In this case, the second and third battery packs are not within the current parallel voltage range, but are lower than the activated battery pack. They could be activated, but due to the unreasonable threshold setting, the second or third battery pack needs to wait for the first battery pack to continue charging, directly satisfying the 1.588V voltage difference. However, by adopting the solution of this application, the switching voltage threshold corresponding to the current parallel voltage range is determined to be 0.364V based directly on the correspondence between the preset parallel voltage range and the switching voltage threshold, and the current parallel voltage range (10V, 25V).

[0104] In the charging state, the controller determines the first extreme voltage and the second extreme voltage as the voltage with the smallest voltage value according to the correspondence between the current state of the parallel system 1150 and the extreme voltage, that is, the first extreme voltage is 54.4V and the second extreme voltage is 54V.

[0105] The voltage difference between the first extreme voltage of 54.4V and the second extreme voltage of 50V is 0.4V, which is greater than the switching voltage threshold of 0.364V. Therefore, the controller 1120 performs a battery pack switching operation. The controller 1120 configures the first battery pack to be disabled and the second battery pack to be enabled.

[0106] In this embodiment, by dynamically adjusting the switching voltage threshold according to the changes in the current parallel voltage range, rather than simply fixing the threshold, the battery pack can meet the switching voltage threshold even if the parallel voltage range is not met after connection. This ensures that the battery pack can participate in charging and discharging in a timely manner after connection, avoiding long waiting times and achieving flexible switching operations.

[0107] Figure 3 This is a second flowchart illustrating a multi-battery pack management method in another exemplary embodiment of this application. This embodiment further illustrates the foregoing embodiment, specifically describing the method by which the controller 1120 determines the switching voltage threshold based on the current parallel voltage range.

[0108] The process in this embodiment is as follows: Figure 3 As shown, it includes the following steps:

[0109] Step 310: Determine the switching voltage threshold based on the current parallel voltage range.

[0110] Step 320: Obtain the upper and lower limits of the current parallel voltage range.

[0111] Specifically, the upper and lower limits of the current parallel voltage range can be obtained based on the current parallel voltage range.

[0112] Step 330: Calculate the difference between the upper limit and the lower limit to obtain the switching voltage threshold.

[0113] After obtaining the upper and lower limits of the current parallel voltage range, the difference between the upper and lower limits is calculated to obtain the voltage difference between the upper and lower limits. The voltage difference between the upper and lower limits is used as the switching voltage threshold.

[0114] It can be understood that the current parallel voltage range is a numerical interval. Calculating the difference between the upper and lower limits of this interval actually calculates the length of the current parallel voltage range. In other words, the switching voltage threshold is determined based on the length of the current parallel voltage range.

[0115] Step 340: Based on the current state of the parallel system 1150 and the battery voltages of the multiple battery packs, determine the first extreme voltage corresponding to all currently activated battery packs and the second extreme voltage corresponding to all currently inactive battery packs.

[0116] Step 350: If the voltage difference between the first extreme voltage and the second extreme voltage is greater than the switching voltage threshold, perform a battery pack switching operation; the battery pack switching operation includes configuring all currently enabled battery packs to be disabled and configuring the battery pack corresponding to the second extreme voltage to be enabled.

[0117] Steps 310, 340, and 350 in this embodiment are similar to steps 210, 230, and 240 in the previous embodiment. To avoid repetition, they will not be described again here.

[0118] In related technologies, to determine whether a battery pack parallel operation needs to be performed, a battery pack is usually selected as a reference battery pack from the currently active battery packs.

[0119] If the reference battery pack is not selected properly, the voltage difference between the newly connected battery pack and the already connected battery pack may exceed the parallel voltage range. This could cause the mutual charging current to exceed the safe range when the load is unloaded (i.e., when the load is disconnected from the equipment), posing a risk of device burnout.

[0120] Figure 4This is a schematic diagram of parallel operation under charging and discharging conditions in related technologies, in which... Figure 4 The left side shows a parallel operation diagram in a discharged state. The first and second battery packs are already in parallel operation. The battery voltage of the second battery pack is greater than that of the first battery pack. When the second battery pack is used as the reference battery pack, a parallel operation voltage range is generated based on the second battery pack. The battery voltage of the first battery pack is less than the lower limit of the parallel operation voltage range. Connecting the third battery pack based on the upper limit of this parallel operation voltage range will cause the voltage difference between the battery voltage of the third battery pack and the battery voltage of the first battery pack to exceed the parallel operation voltage range.

[0121] Figure 4 The diagram on the right shows the parallel operation in charging mode. The first and second battery packs are already in parallel operation. The battery voltage of the second battery pack is greater than that of the first battery pack. When the first battery pack is used as the reference battery pack, a parallel operation voltage range is generated based on the first battery pack. The battery voltage of the second battery pack is greater than the upper limit of the parallel operation voltage range. When the third battery pack is connected based on the lower limit of this parallel operation voltage range, the voltage difference between the battery voltage of the third battery pack and the battery voltage of the second battery pack will exceed the parallel operation voltage range.

[0122] Therefore, when determining the parallel voltage range, how to determine a suitable reference battery pack so that the voltage difference between any two battery packs within the parallel voltage range is within the safe voltage difference range is also an important issue in multi-battery pack management.

[0123] Figure 5 This is a third flowchart illustrating a multi-battery pack management method in another exemplary embodiment. This embodiment is a further improvement on the foregoing embodiments, the main improvement being that: this embodiment proposes a specific method for determining the current parallel voltage range.

[0124] The process in this embodiment is as follows: Figure 5 As shown, it includes the following steps:

[0125] Step 510: Based on the current state of the parallel system 1150 and the battery voltages of the multiple battery packs, determine the first extreme voltage corresponding to all currently activated battery packs.

[0126] Step 520: The battery pack corresponding to the first extreme voltage is determined as the reference battery pack.

[0127] Specifically, one battery pack can be selected from all currently active battery packs as a reference battery pack. For example, the battery pack corresponding to the first extreme voltage among all currently active battery packs can be selected as the reference battery pack.

[0128] For example, in the charging state, the battery pack with the highest battery voltage among all currently activated battery packs is determined as the reference battery pack; in the discharging state, the battery pack with the lowest battery voltage among all currently activated battery packs is determined as the reference battery pack.

[0129] Specifically, when the parallel system 1150 is in the charging state, the battery pack with the highest battery voltage among all currently active battery packs is determined as the reference battery pack. Then, when paralleling a battery pack based on the parallel voltage range calculated from this reference battery pack, since the reference battery pack has the highest battery voltage, the voltage difference between the newly added battery pack and the maximum voltage of the already paralleled battery pack will not exceed the parallel voltage range. Therefore, when the load is unloaded or the input power is disconnected, the mutual charging current between all active battery packs is within a safe range, avoiding device damage.

[0130] When the parallel system 1150 is in a discharging state, the battery pack with the lowest battery voltage among all currently active battery packs is identified as the reference battery pack. Then, when paralleling a battery pack based on the parallel voltage range calculated from this reference battery pack, since the reference battery pack has the lowest battery voltage, the voltage difference between the newly added battery pack and the lowest voltage in the already paralleled battery pack will not exceed the parallel voltage range. Therefore, when the load is unloaded or the input power is disconnected, the mutual charging current between all active battery packs is within a safe range, avoiding device damage.

[0131] Step 530: Determine the current parallel voltage range based on the battery voltage of the reference battery pack, the current of the reference battery pack, and the preset correlation between the current and the parallel voltage difference range.

[0132] Specifically, after determining the reference battery pack, the parallel voltage difference range corresponding to the current of the reference battery pack is determined based on the correlation between the preset current and the parallel voltage difference range, according to the current of the reference battery pack.

[0133] The current parallel voltage range is obtained by adding the battery voltage of the reference battery pack to the upper and lower limits of the parallel voltage difference range. The controller 1120 then determines whether to perform a battery pack parallel operation based on the current parallel voltage range.

[0134] The preset relationship between the current and the parallel voltage difference range can be as shown in Table 1, or it can be other relationships. This application does not make any specific limitation on this.

[0135] Step 510 in this embodiment is similar to the steps in the aforementioned embodiment 230. To avoid repetition, it will not be described again here.

[0136] To facilitate understanding, the multi-battery pack management method of this embodiment will be illustrated with specific examples below:

[0137] The parallel system 1150 is currently charging. The currently activated battery packs are the first battery pack, the second battery pack, and the third battery pack. The battery voltage of the first battery pack is 25.5V, the battery voltage of the second battery pack is 25.4V, and the battery voltage of the third battery pack is 25.45V.

[0138] During charging, the controller 1120 determines the minimum battery voltage among all currently activated battery packs as the first extreme voltage, which is 25.4V. The controller 1120 then determines the first battery pack corresponding to the first extreme voltage as the reference battery pack.

[0139] The controller 1120 obtains the current of the first battery pack as 10A. According to Table 1, the current parallel voltage difference range is (-264mV, +100mV). The controller 1120 adds the battery voltage of the first battery pack to the current parallel voltage difference range to determine the current parallel voltage range [25.4V-0.264V, 25.4V+0.1V], i.e. [25.136V, 25.5V]. Based on the current parallel voltage range [25.136V, 25.5V] and the battery voltage of the currently inactive battery pack, the controller 1120 determines whether to perform a battery pack parallel operation.

[0140] Figure 6 This is a schematic diagram of parallel operation under charging and discharging conditions in this application, wherein, Figure 6 The left side shows a schematic diagram of parallel operation in a discharged state. The first and second battery packs are already in parallel operation. The battery voltage of the second battery pack is greater than that of the first battery pack. The battery pack with the lowest battery voltage among all currently active battery packs is designated as the reference battery pack; that is, the first battery pack is used as the reference battery pack. A parallel operation voltage range is generated based on the first battery pack. The third battery pack is then connected to the parallel operation voltage range (i.e., the third battery pack is activated). Even if the battery voltage of the third battery pack happens to be the upper limit of the parallel operation voltage range, the voltage difference between the battery voltage of the third battery pack and the battery voltage of the first battery pack will not exceed the parallel operation voltage range.

[0141] Figure 6The diagram on the right shows the parallel operation during charging. The first and second battery packs are already in parallel operation. The battery voltage of the second battery pack is higher than that of the first battery pack. The battery pack with the highest voltage among all currently active battery packs is designated as the reference battery pack; that is, the second battery pack is used as the reference battery pack. A parallel operation voltage range is generated based on the second battery pack. At this time, the third battery pack is connected according to the parallel operation voltage range. Even if the battery voltage of the third battery pack happens to be the lower limit of the parallel operation voltage range, the voltage difference between the battery voltage of the third battery pack and the battery voltage of the second battery pack will not exceed the parallel operation voltage range.

[0142] In this embodiment, by determining the battery pack corresponding to the first extreme voltage as the reference battery pack and determining the current parallel voltage range based on the reference battery pack, it can be ensured that the voltage difference between the battery pack of the newly connected battery pack and all currently activated battery packs is always within the current parallel voltage range, thus avoiding the risk of device burnout caused by exceeding the current parallel voltage range as mentioned above.

[0143] Figure 7 This is a fourth flowchart illustrating a multi-battery pack management method in another exemplary embodiment. This embodiment is a further improvement on the foregoing embodiments, the main improvement being that: this embodiment proposes a specific process for the controller 1120 to perform parallel operation.

[0144] The process in this embodiment is as follows: Figure 7 As shown, it includes the following steps:

[0145] Step 710: Based on the current state of the parallel system 1150 and the battery voltages of the multiple battery packs, determine the first extreme voltage corresponding to all currently activated battery packs.

[0146] Step 720: The battery pack corresponding to the first extreme voltage is determined as the reference battery pack.

[0147] Step 730: Determine the current parallel voltage range based on the battery voltage of the reference battery pack, the current of the reference battery pack, and the preset correlation between the current and the parallel voltage difference range.

[0148] Step 740: When any battery pack among all currently inactive battery packs meets the parallel operation conditions, configure the battery pack that meets the parallel operation conditions as active; the parallel operation conditions are: the battery voltage falls within the current parallel operation voltage range.

[0149] Specifically, the parallel operation condition is that the battery voltage of the battery pack falls within the current parallel operation voltage range, that is, the battery voltage of the battery pack is between the upper and lower limits of the parallel operation voltage range, or it can be either the upper or lower limit of the parallel operation voltage range.

[0150] The controller 1120 detects the battery voltage of all currently inactive battery packs in real time. When any battery pack among all currently inactive battery packs meets the parallel operation conditions, that is, when the battery voltage of any battery pack among all currently inactive battery packs is within the parallel operation voltage range, the controller 1120 performs a parallel operation on the battery pack that meets the parallel operation conditions, that is, configures the battery pack that meets the parallel operation conditions as active.

[0151] Steps 710, 720, and 730 in this embodiment are similar to steps 510, 520, and 530 in the previous embodiments. To avoid repetition, they will not be described again here.

[0152] To facilitate understanding, the multi-battery pack management method of this embodiment will be illustrated with specific examples below:

[0153] The parallel system 1150 is currently charging. The currently active battery packs are the first, second, and third battery packs. The battery voltage of the first battery pack is 25.5V, the second battery pack is 25.4V, and the third battery pack is 25.45V. The currently inactive battery packs are the fourth and fifth battery packs. The battery voltage of the fourth battery pack is 25.6V, and the fifth battery pack is 25.3V.

[0154] During charging, the controller 1120 determines the minimum battery voltage among all currently activated battery packs as the first extreme voltage, which is 25.4V. The controller 1120 then determines the first battery pack corresponding to the first extreme voltage as the reference battery pack.

[0155] The controller 1120 obtains the current of the first battery pack as 10A. According to Table 1, the current parallel voltage difference range is (-264mV, +100mV). The controller 1120 adds the battery voltage of the first battery pack to the current parallel voltage difference range to determine the current parallel voltage range [25.4V-0.264V, 25.4V+0.1V], that is, [25.136V, 25.5V].

[0156] The controller 1120 determines whether to perform a battery pack parallel operation based on the current parallel voltage range [25.136V, 25.5V] and the battery voltage of the currently inactive battery pack. If the battery voltage of the fourth battery pack (25.6V) is not within the current parallel voltage range [25.136V, 25.5V], and the battery voltage of the fifth battery pack (25.3V) is within the current parallel voltage range [25.136V, 25.5V], then the controller will configure the fifth battery pack as active.

[0157] In this embodiment, by selecting battery packs that meet the parallel operation conditions from all currently inactive battery packs and configuring the battery packs that meet the conditions as active, the volume of currently active battery packs can be expanded, ensuring normal charging and discharging.

[0158] Figure 8 This is a fifth flowchart illustrating a multi-battery pack management method in another exemplary embodiment. This embodiment is a further improvement on the foregoing embodiments, the main improvement being that: this embodiment proposes a specific process for the controller 1120 to perform an exit operation.

[0159] The process in this embodiment is as follows: Figure 8 As shown, it includes the following steps:

[0160] Step 810: Based on the current state of the parallel system 1150 and the battery voltages of the multiple battery packs, determine the first extreme voltage corresponding to all currently activated battery packs.

[0161] Step 820: The battery pack corresponding to the first extreme voltage is determined as the reference battery pack.

[0162] Step 830: Determine the current parallel voltage range based on the battery voltage of the reference battery pack, the current of the reference battery pack, and the preset correlation between the current and the parallel voltage difference range.

[0163] Step 840: If any battery pack among all currently enabled battery packs does not meet the parallel operation conditions, configure the battery pack that does not meet the parallel operation conditions to be disabled; the parallel operation conditions are: the battery voltage of the battery pack falls within the current parallel operation voltage range.

[0164] Specifically, the parallel operation condition is that the battery voltage of the battery pack falls within the current parallel operation voltage range, that is, the battery voltage of the battery pack is within the parallel operation voltage range.

[0165] The controller 1120 monitors the battery voltage of all currently enabled battery packs in real time. When any battery pack among all currently enabled battery packs does not meet the parallel operation conditions, that is, when the battery voltage of any battery pack among all currently enabled battery packs is not within the parallel operation voltage range, the controller 1120 performs an exit operation on the battery pack that does not meet the parallel operation conditions, that is, it sets the battery pack that does not meet the parallel operation conditions from enabled to disabled.

[0166] Steps 810, 820, and 830 in this embodiment are similar to steps 510, 520, and 530 in the previous embodiments. To avoid repetition, they will not be described again here.

[0167] To facilitate understanding, the multi-battery pack management method of this embodiment will be illustrated with specific examples below:

[0168] The parallel system 1150 is currently charging. The currently activated battery packs are the first battery pack, the second battery pack, and the third battery pack. The battery voltage of the first battery pack is 25.5V, the battery voltage of the second battery pack is 25.4V, and the battery voltage of the third battery pack is 25.45V.

[0169] During charging, the controller 1120 determines the minimum battery voltage among all currently activated battery packs as the first extreme voltage, which is 25.4V. The controller 1120 then determines the first battery pack corresponding to the first extreme voltage as the reference battery pack.

[0170] The controller 1120 obtains the current of the first battery pack as 10A. According to Table 1, the current parallel voltage difference range is (-264mV, +100mV). The controller 1120 adds the battery voltage of the first battery pack to the current parallel voltage difference range to determine the current parallel voltage range [25.4V-0.264V, 25.4V+0.1V], that is, [25.136V, 25.5V].

[0171] After a period of charging, the battery voltage of the first battery pack is 25.6V, the battery voltage of the second battery pack is 25.45V, and the battery voltage of the third battery pack is 25.55V. At this point, the current parallel operation range is redefined as [25.45V-0.264V, 25.45V+0.1V], or [25.186V, 25.55V]. Since the battery voltage of the first battery pack does not fall within this range, a deactivation operation is performed on the first battery pack, configuring it as inactive.

[0172] In this embodiment, by filtering out battery packs that do not meet the parallel operation conditions from all currently activated battery packs and removing them from the parallel operation, the safety hazards caused by unsuitable battery packs are avoided.

[0173] Figure 9 This is a sixth flowchart illustrating a multi-battery pack management method in another exemplary embodiment. This embodiment is a further improvement on the foregoing embodiments, the main improvement being that it proposes a specific method for dynamically updating the current parallel voltage range.

[0174] The process in this embodiment is as follows: Figure 9 As shown, it includes the following steps:

[0175] Step 910: Based on the current state of the parallel system 1150 and the battery voltages of the multiple battery packs, determine the first extreme voltage corresponding to all currently activated battery packs.

[0176] Step 920: The battery pack corresponding to the first extreme voltage is determined as the reference battery pack.

[0177] Step 930: Determine the current parallel voltage range based on the battery voltage of the reference battery pack, the current of the reference battery pack, and the preset correlation between the current and the parallel voltage difference range.

[0178] Step 940: When all currently enabled battery packs change, redetermine the first extreme voltage and the reference battery pack.

[0179] Specifically, when the controller 1120 performs an exit operation, a switching operation, or a parallel operation, all currently enabled battery packs will change.

[0180] For example, when controller 1120 performs an exit operation, the number of all currently active battery packs will decrease; when controller 1120 performs a switching operation, all currently active battery packs will be replaced; when controller 1120 performs a parallel operation, the number of all currently active battery packs will increase.

[0181] When all currently active battery packs change, the first extreme voltage is re-determined from the battery voltages of all currently active battery packs after the change. The re-determined first extreme voltage may not have changed, that is, the re-determined first extreme voltage is still the first extreme voltage corresponding to the current active battery packs before the change; the re-determined first extreme voltage may also have changed, that is, the re-determined first extreme voltage is not the first extreme voltage corresponding to the current active battery packs before the change.

[0182] There is a corresponding relationship between the reference battery pack and the first extreme voltage. After redetermining the first extreme voltage, the reference battery pack also needs to be redetermined. The process of redetermining the reference battery pack is as follows: the battery pack corresponding to the newly determined first extreme voltage is designated as the reference battery pack.

[0183] Step 950: When the reference battery pack changes, update the current parallel voltage range.

[0184] Specifically, when the redefined first extreme voltage changes, the reference battery pack also changes; when the redefined first extreme voltage does not change, the reference battery pack does not change.

[0185] When the reference battery pack remains unchanged, the current parallel voltage range will not change. When the reference battery pack changes, based on the newly determined reference battery pack current, the parallel voltage difference range corresponding to the newly determined reference battery pack current is obtained from the preset correlation between current and parallel voltage difference range. The parallel voltage difference range is updated. The battery voltage of the newly determined reference battery pack is added to the upper and lower limits of the updated parallel voltage difference range to obtain the updated current parallel voltage range.

[0186] Steps 910, 920, and 930 in this embodiment are similar to steps 510, 520, and 530 in the previous embodiments. To avoid repetition, they will not be described again here.

[0187] In this embodiment, by re-determining the first extreme voltage and the reference battery pack when all currently enabled battery packs change, and updating the current parallel voltage range when the reference battery pack changes, the current parallel voltage range is dynamically updated, enabling the controller 1120 to more flexibly perform battery pack switching operations and battery pack parallel operations.

[0188] Figure 10 This is a seventh flowchart illustrating a multi-battery pack management method in another exemplary embodiment. This embodiment is a further improvement on the foregoing embodiments, the main improvement being that this embodiment proposes a process for activating a battery pack when no other battery pack in the parallel system is activated.

[0189] The process in this embodiment is as follows: Figure 10 As shown, it includes the following steps:

[0190] Step 1010: Obtain battery pack data for each battery pack. The battery pack data includes: battery voltage, current, and error code for each battery pack.

[0191] Specifically, the controller 1120 acquires battery pack data for each battery pack, including: battery voltage, current, and error code for each battery pack. The error code is used to indicate whether there is an error in the battery pack.

[0192] The battery pack data for each battery pack can be obtained periodically. For example, a fixed time can be preset, and the battery pack data for each battery pack can be obtained once at fixed intervals; alternatively, a correspondence between the interval acquisition time and the number of battery packs can be preset, where the more battery packs there are, the shorter the interval acquisition time, so as to flexibly obtain the battery pack data for each battery pack.

[0193] Battery pack data for each battery pack can also be obtained periodically. For example, battery pack data for each battery pack can be obtained once when a change occurs.

[0194] The method of obtaining battery pack data for each battery pack can also be a combination of periodic and irregular acquisition.

[0195] Step 1020: If no battery pack is currently enabled, determine the target battery pack based on all battery pack data.

[0196] Specifically, when there is no active battery pack, the controller 1120 filters all acquired battery pack data from at least one of the three dimensions: battery voltage, current, and error code, and selects the battery pack corresponding to the filtered target data as the target battery pack.

[0197] For example, in the charging state, the battery pack with no errors and the lowest battery voltage is identified as the target battery pack; in the discharging state, the battery pack with no errors and the highest battery voltage is identified as the target battery pack.

[0198] Specifically, when the parallel system 1150 is in a charging state, the battery pack data with no errors and the lowest battery voltage is selected from all battery pack data, and the battery pack corresponding to the battery pack data with no errors and the lowest battery voltage is selected as the target battery pack.

[0199] When charging, selecting the target battery pack with no errors ensures that the target battery pack is successfully activated. Selecting the battery pack with the lowest battery voltage ensures that the target battery pack is also charging after activation.

[0200] When the parallel system 1150 is in a discharging state, the battery pack data with no errors and the highest battery voltage is selected from all battery pack data, and the battery pack corresponding to the battery pack data with no errors and the highest battery voltage is selected as the target battery pack.

[0201] When in a discharge state, selecting the target battery pack as the error-free battery pack ensures that the target battery pack is successfully activated. The battery pack with the highest battery voltage ensures that the target battery pack remains in a discharge state after activation.

[0202] Step 1030: Configure the target battery pack to be enabled.

[0203] Specifically, the controller 1120 configures the target battery pack to be enabled, and then uses the target battery pack as the initial reference battery pack to obtain the initial parallel voltage range. The specific process is as follows:

[0204] First, based on the target battery pack's current, the corresponding parallel voltage difference range is obtained from the preset correlation between current and parallel voltage difference range. Then, the target battery pack's battery voltage is added to both the upper and lower limits of this range to obtain the initial parallel voltage range. Finally, other battery packs are connected to the parallel system according to the initial parallel voltage range. After connecting the other battery packs, the process proceeds as follows: Figure 10 The flowchart shown redefines the parallel voltage range.

[0205] In this embodiment, by determining the target battery pack for activation based on all battery pack data when the energy storage device is first put into use and no battery pack is activated, the battery pack that meets the activation requirements can be accurately screened.

[0206] Figure 11 This is a structural schematic diagram of the energy storage device of this application, as shown below. Figure 11 As shown, the energy storage device 1100 may include: a parallel port 1110, a controller 1120, a memory 1130, and a battery pack 1140.

[0207] Parallel connection port 1110 is used to connect to other energy storage devices, which can be independently charged and discharged battery packs or energy storage devices different from those described in this application. There can also be multiple parallel connection ports 1110, such as... Figure 11 As shown, there are a first parallel port, a second parallel port, and a third parallel port. The first parallel port is connected to another energy storage device, which contains a battery pack. The second energy storage device is connected to an independent battery pack. The third parallel port is not connected to any device.

[0208] The controller 1120 is connected to each battery pack, and is also connected to battery pack 1140, the second battery pack (the battery pack in the energy storage device connected to the first parallel port), and the third battery pack (an independent battery pack connected to the second parallel port). The memory 1430 stores computer-readable instructions, which, when executed by the controller, implement any of the multi-battery management methods described above.

[0209] Energy storage device 1100 also includes Figure 11 The charging / discharging port (not shown) is connected to the battery pack 1140, which in turn connects to the power conversion device 1170 to enable external discharge or charging.

[0210] It is understood that in the energy storage device 1100, the charging and discharging port can include a charging port and a discharging port, or it can be a composite port that can be used for both discharging and charging. When the charging and discharging port includes a charging port and a discharging port respectively, multiple energy storage devices and / or battery packs can be connected through the parallel port, receive charging through the same charging port, and discharge through the same discharging port. When the energy storage device 1100 is an independent battery pack, it can include a port and a battery management system (BMS) containing a microcontroller (MCU). This port can serve as a charging and discharging interface when the battery pack is directly connected to a load or power supply, and as a parallel port when the battery pack is connected to other battery packs. The battery pack can also be connected to the power conversion device 1170 through this port, and discharge or receive charging through the power conversion device 1170. When multiple battery packs are paralleled, each battery pack is connected to the same port of the power conversion device 1170 through this port, and discharges or receives charging uniformly.

[0211] In some embodiments, memory 1130 may include high-speed random access memory, and may also include non-volatile memory, such as hard disk, memory, plug-in hard disk, smart media card (SMC), secure digital (SD) card, flash card, at least one disk storage device, flash memory device, or other volatile solid-state storage device.

[0212] Figure 12 This is a schematic diagram of the energy storage system of this application, as shown below. Figure 12 As shown, the energy storage system 1200 includes at least two energy storage devices connected through a parallel port 1110, and at least one of the energy storage devices is the aforementioned energy storage device 1100.

[0213] Specifically, according to embodiments of this application, the processes described above with reference to the flowcharts can be implemented as computer software programs. For example, embodiments of this application include a computer program product comprising a computer program carried on a computer-readable medium, the computer program including a computer program for performing the methods shown in the flowcharts. In such embodiments, the computer program can be downloaded and installed from a network via a communication component, and / or installed from a removable medium. When the computer program is executed by a central processing unit (CPU), it performs various functions defined in the system of this application.

[0214] It should be noted that the computer-readable medium shown in the embodiments of this application can be a computer-readable signal medium or a computer-readable storage medium, or any combination of the two. A computer-readable storage medium can be, for example, an electrical, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device, or any combination thereof. More specific examples of a computer-readable storage medium may include, but are not limited to: an electrical connection having one or more wires, a portable computer disk, a hard disk, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM), flash memory, optical fiber, portable compact disc read-only memory (CD-ROM), optical storage device, magnetic storage device, or any suitable combination thereof. In this application, a computer-readable storage medium can be any tangible medium containing or storing a program that can be used by or in conjunction with an instruction execution system, apparatus, or device. In this application, a computer-readable signal medium can include a data signal propagated in baseband or as part of a carrier wave, carrying a computer-readable computer program. The transmitted data signal can take various forms, including but not limited to electromagnetic signals, optical signals, or any suitable combination thereof. The computer-readable signal medium can also be any computer-readable medium other than a computer-readable storage medium, which can send, propagate, or transmit a program for use by or in connection with an instruction execution system, apparatus, or device. The computer program contained on the computer-readable medium can be transmitted using any suitable medium, including but not limited to wireless, wired, etc., or any suitable combination thereof.

[0215] The flowcharts and block diagrams in the accompanying drawings illustrate the architecture, functionality, and operation of possible implementations of systems, methods, and computer program products according to various embodiments of this application. Each block in a flowchart or block diagram may represent a module, segment, or portion of code, which contains one or more executable instructions for implementing a specified logical function. It should also be noted that in some alternative implementations, the functions indicated in the blocks may occur in a different order than those indicated in the drawings. For example, two consecutively indicated blocks may actually be executed substantially in parallel, and they may sometimes be executed in reverse order, depending on the functions involved. It should also be noted that each block in a block diagram or flowchart, and combinations of blocks in a block diagram or flowchart, can be implemented using a dedicated hardware-based system that performs the specified function or operation, or using a combination of dedicated hardware and computer instructions.

[0216] Another aspect of this application provides a computer-readable storage medium storing a computer program that, when executed by a processor, implements the aforementioned multi-battery pack management method. This computer-readable storage medium may be included in the energy storage device described in the above embodiments, or it may exist independently and not incorporated into the energy storage device.

[0217] Another aspect of this application provides a computer program product or computer program including computer instructions stored in a computer-readable storage medium. A processor of a computer device reads the computer instructions from the computer-readable storage medium and executes the computer instructions, causing the computer device to perform the multi-battery pack management method provided in the various embodiments described above.

[0218] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any changes or substitutions within the technical scope disclosed in this application should be covered within the scope of protection of this application.

Claims

1. A multi-battery pack management method, applied to a controller, characterized in that, The controller is connected to multiple battery packs, which form a parallel system. The multi-battery pack management method includes: Select a reference battery pack from all currently active battery packs, and determine the corresponding current parallel voltage range based on the battery voltage of the reference battery pack, the current of the reference battery pack, and the preset correlation between the current and the parallel voltage difference range. The switching voltage threshold is determined based on the current parallel voltage range, wherein the larger the current parallel voltage range, the larger the switching voltage threshold. Based on the current state of the parallel system and the battery voltages of the multiple battery packs, determine the first extreme voltage corresponding to all currently activated battery packs and the second extreme voltage corresponding to all currently inactive battery packs; When the voltage difference between the first extreme voltage and the second extreme voltage is greater than the switching voltage threshold, a battery pack switching operation is performed; the battery pack switching operation includes configuring all currently enabled battery packs to be disabled and configuring the battery pack corresponding to the second extreme voltage to be enabled.

2. The multi-battery pack management method according to claim 1, characterized in that, Based on the current state of the parallel system and the battery voltages of the multiple battery packs, determine the first extreme voltage corresponding to all currently activated battery packs, and the second extreme voltage corresponding to all currently inactive battery packs, including: In the charging state, the minimum battery voltage among all currently activated battery packs is determined as the first extreme voltage, and the minimum battery voltage among all currently inactive battery packs is determined as the second extreme voltage; or, In the discharge state, the maximum battery voltage among all currently activated battery packs is determined as the first extreme voltage, and the maximum battery voltage among all currently inactive battery packs is determined as the second extreme voltage.

3. The multi-battery pack management method according to claim 1, characterized in that, The step of determining the switching voltage threshold based on the current parallel voltage range includes: Obtain the upper and lower limits of the current parallel voltage range; The difference between the upper limit value and the lower limit value is used to obtain the switching voltage threshold.

4. The multi-battery pack management method according to claim 1, characterized in that, The method further includes: The battery pack corresponding to the first extreme voltage is determined as the reference battery pack.

5. The multi-battery pack management method according to claim 4, characterized in that, The method further includes: When any of the battery packs currently not enabled meets the parallel operation conditions, the battery pack that meets the parallel operation conditions will be configured to be enabled; the parallel operation conditions are: the battery voltage of the battery pack falls within the current parallel operation voltage range.

6. The multi-battery pack management method according to claim 4, characterized in that, The method further includes: If any of the currently enabled battery packs does not meet the parallel operation conditions, the battery pack that does not meet the parallel operation conditions will be configured to be disabled; the parallel operation conditions are: the battery voltage of the battery pack falls within the current parallel operation voltage range.

7. The multi-battery pack management method according to any one of claims 4-6, characterized in that, The method further includes: When all currently enabled battery packs change, the first extreme voltage and the reference battery pack are re-determined; When the reference battery pack changes, the current parallel voltage range is updated.

8. The multi-battery pack management method according to claim 4, characterized in that, The step of determining the battery pack corresponding to the first extreme voltage as the reference battery pack includes: In the charging state, the battery pack with the highest battery voltage among all currently activated battery packs is determined as the reference battery pack; or, In the discharge state, the battery pack with the lowest battery voltage among all currently activated battery packs is determined as the reference battery pack.

9. The multi-battery pack management method according to claim 1, characterized in that, The method further includes: Obtain battery pack data for each battery pack, including: battery voltage, current, and error code for each battery pack; When no battery pack is currently in use, the target battery pack is determined based on all the battery pack data. Configure the target battery pack to be enabled.

10. An energy storage device, characterized in that, The energy storage device includes a parallel port, a controller, a memory, and a battery pack; The parallel port is used to connect with other energy storage devices; The controller is connected to each battery pack; The memory stores computer-readable instructions, which, when executed by the controller, implement the multi-battery pack management method as described in any one of claims 1-9.

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