Battery power control method and system in battery pack, converter, storage medium

Abstract

The disclosure provides a battery power control method and system, a converter and a storage medium in a battery pack. The method belongs to the technical field of power electronics, and comprises the following steps: determining a first droop coefficient according to a current state of charge of a first battery unit connected in series; determining a second droop coefficient according to a current power limit value of the first battery unit; determining a target droop coefficient of the first battery unit according to the first droop coefficient and the second droop coefficient; and controlling the operating power of the first battery unit according to the target droop coefficient. In this way, the power of the battery unit can be controlled comprehensively according to the state of charge and the power limit value, and the accuracy and safety are improved.

Description

Technical Field

[0001] This disclosure relates to the field of power electronics technology, and in particular to a battery power control method and system, converter, and storage medium in a battery pack. Background Technology

[0002] An energy storage battery pack is an energy storage system composed of multiple battery cells. It can store electrical energy and supply it to loads or the power grid when needed. In related technologies, in order to achieve coordinated operation of the parallel branches or battery cells within the battery pack, the main control method used is to adjust the operating power of the battery cells solely based on their State of Charge (SOC) through droop control. However, in reality, the charging and discharging power capabilities of battery cells are dynamically affected by various factors. Power allocation control based solely on SOC may result in a battery cell being allocated a power task exceeding its current safe power limit, which not only affects safety but also the instantaneous power change rate of the energy storage battery pack. Summary of the Invention

[0003] This disclosure provides a battery power control method and system, converter, and storage medium in a battery pack.

[0004] In a first aspect, this disclosure provides a battery power control method for a battery pack, the battery pack including at least two battery cells and at least two converters, each battery cell being connected in series with a converter to form a branch, and different branches being connected in parallel, the method being applied to any one of the converters, the method including: determining a first droop coefficient based on the current state of charge of the first battery cell connected in series; determining a second droop coefficient based on the current power limit of the first battery cell; determining a target droop coefficient of the first battery cell based on the first droop coefficient and the second droop coefficient; and controlling the operating power of the first battery cell based on the target droop coefficient.

[0005] Secondly, this disclosure provides a converter, which is any one of the converters in a battery pack. The battery pack includes at least two battery cells and at least two converters. Each battery cell is connected in series with one of the converters to form a branch, and different branches are connected in parallel. The converter is used for:

[0006] A first droop coefficient is determined based on the current state of charge of the first battery cell connected in series; a second droop coefficient is determined based on the current power limit of the first battery cell; a target droop coefficient of the first battery cell is determined based on the first droop coefficient and the second droop coefficient; and the operating power of the first battery cell is controlled based on the target droop coefficient.

[0007] Thirdly, this disclosure provides a battery power control system for a battery pack. The system includes a battery pack and a host. The battery pack includes at least two battery cells and at least two converters. Each battery cell is connected in series with one of the converters to form a branch. Different branches are connected in parallel. The host communicates with each of the converters. The converters are used to execute the battery power control method for the battery pack described in the above embodiments.

[0008] Fourthly, this disclosure provides a computer-readable storage medium having a computer program stored thereon, wherein the computer program, when executed by a processor, implements the above-described battery power control method in a battery pack.

[0009] The embodiments provided in this disclosure determine a first droop coefficient based on the current state of charge of the first battery cell, determine a second droop coefficient based on the current power limit of the first battery cell, and determine a target droop coefficient for the first battery cell based on the first and second droop coefficients. Then, the operating power of the first battery cell is controlled based on the target droop coefficient. In this way, the target droop coefficient can be determined by combining the state of charge and the power limit, which can ensure that the operating power of each battery cell is within its respective power limit, thereby improving safety. Furthermore, while ensuring safety and the lifespan of the battery pack, it can also maximize the instantaneous power change rate of the battery pack and improve the overall utilization efficiency.

[0010] It should be understood that the description in this section is not intended to identify key or essential features of the embodiments of this disclosure, nor is it intended to limit the scope of this disclosure. Other features of this disclosure will become readily apparent from the following description. Attached Figure Description

[0011] The accompanying drawings are provided to further illustrate the present disclosure and form part of the specification. They are used together with the embodiments of the present disclosure to explain the disclosure and do not constitute a limitation thereof. The above and other features and advantages will become more apparent to those skilled in the art from the detailed example embodiments described with reference to the accompanying drawings, which are shown below.

[0012] Figure 1 This is a schematic diagram of the system structure of a battery pack according to an embodiment of the present disclosure.

[0013] Figure 2 This is a block diagram illustrating the droop control principle of the converter in an embodiment of this disclosure.

[0014] Figure 3 This is a schematic diagram showing the relationship between the total power of the battery pack and the operating power of each battery cell under relevant technologies.

[0015] Figure 4This is a flowchart of a battery power control method in a battery pack, provided as an embodiment of the present disclosure.

[0016] Figure 5 This is a schematic diagram showing the relationship between the total power of the battery pack and the operating power of each battery cell in an embodiment of this disclosure.

[0017] Figure 6 This is a block diagram of a battery power control system in a battery pack, provided as an embodiment of the present disclosure.

[0018] Figure 7 This is a block diagram of an electronic device provided in an embodiment of the present disclosure. Detailed Implementation

[0019] To enable those skilled in the art to better understand the technical solutions of this disclosure, exemplary embodiments of this disclosure are described below with reference to the accompanying drawings, including various details of the embodiments of this disclosure to aid understanding. These should be considered merely exemplary. Therefore, those skilled in the art should recognize that various changes and modifications can be made to the embodiments described herein without departing from the scope and spirit of this disclosure. Similarly, for clarity and conciseness, descriptions of well-known functions and structures are omitted in the following description.

[0020] Where there is no conflict, the various embodiments of this disclosure and the features thereof in the embodiments may be combined with each other.

[0021] As used herein, the term “and / or” includes any and all combinations of one or more related enumerated entries.

[0022] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit this disclosure. As used herein, the singular forms “a” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will also be understood that when the terms “comprising” and / or “made of” are used in this specification, the presence of the stated feature, integral, step, operation, element, and / or component is specified, but the presence or addition of one or more other features, integrals, steps, operations, elements, components, and / or groups thereof is not excluded. Words such as “connected” or “linked” are not limited to physical or mechanical connections but can include electrical connections, whether direct or indirect.

[0023] Unless otherwise specified, all terms used herein (including technical and scientific terms) have the same meaning as commonly understood by one of ordinary skill in the art. It will also be understood that terms such as those defined in commonly used dictionaries should be interpreted as having a meaning consistent with their meaning in the context of the relevant art and this disclosure, and will not be interpreted as having an idealized or overly formal meaning, unless expressly so defined herein.

[0024] See Figure 1 The diagram shown is a schematic representation of the system structure of a battery pack according to an embodiment of this disclosure. Figure 1 As shown, the battery pack includes at least two battery cells and at least two converters. Each battery cell is connected in series with one converter to form a branch, and different branches are connected in parallel. The charging and discharging power of the battery cells can be controlled by controlling the power of the converters, and the coordinated control of multiple converters can be achieved through droop control.

[0025] For example, the converter can be a bidirectional DC-DC converter (DC-DC converter), which includes buck-boost conversion circuits and a controller, and can convert DC power of one voltage level to DC power of another voltage level.

[0026] See Figure 2 The diagram shown is a block diagram of the droop control principle of the converter in this embodiment. The voltage loop in the droop control is calculated using the following formula.

[0027]

[0028] in, This is the filtered value for the output current of the battery cell. The reference voltage is k, which is the droop coefficient. The value of k is inversely proportional to the charging or discharging power of the battery cell it controls, thereby realizing automatic power distribution among different battery cells.

[0029] like Figure 2 In the middle, the system's desired reference voltage can be set. To achieve power distribution, the reference voltage cannot be used directly. Instead, the outer voltage loop can be calculated based on the battery cell's output current, reference voltage, and droop factor. The outer voltage loop compares the voltage with the actual system voltage. The voltage loop proportional-integral (PI) controller is mainly used to eliminate static errors and outputs a current command. Its main goal is to stabilize the voltage at ; and then with The current-loop PI controller, which compares the current command with the actual output current i of the battery cell, is mainly used to quickly and accurately track the current command and generate a signal to drive the switching transistors in the converter. Its main goal is to enable the battery cell to output current. The magnitude of the current enables voltage-current dual closed-loop droop control.

[0030] In related technologies, the calculation of the droop factor is usually only related to the SOC of the battery cell. The larger the SOC, the greater the discharge power and the smaller the charging power. That is, the operating power of each battery cell is mainly allocated according to its SOC. However, as the total power demand increases, the operating power of each battery cell still increases according to the SOC ratio until the operating power of a certain battery cell reaches its power limit. This will cause that battery cell to work at the limit point, while the remaining power demand will continue to be allocated by other battery cells according to their SOC ratio.

[0031] For example, taking a battery pack containing two battery cells as an example, such as Figure 3 The diagram illustrates the relationship between the total power of the battery pack and the operating power of each battery cell under relevant technologies. It assumes that the power limit for battery cell 1 is 4kW, the power limit for battery cell 2 is 2kW, the droop factor calculated based on its SOC for battery cell 1 is 1, and the droop factor calculated based on its SOC for battery cell 2 is 0.8. Figure 3 As shown, as the total power increases, the power of battery cell 2 reaches the limit first, and then battery cell 2 continues to work at 2kW, while the power of battery cell 1 does not reach the limit. This results in the two battery cells reaching their power limits at different times when the total power is large. There may be a single battery cell that operates at the power limit for a long time, which affects safety and also leads to a smaller instantaneous power change rate of the energy storage battery pack system.

[0032] Therefore, to address this problem, this disclosure provides a battery power control method in a battery pack, which can determine the target droop coefficient of the battery cell by comprehensively considering the current state of charge and its power limit. This enables adaptive collaborative droop control that integrates the state of charge and power limit, thereby achieving intelligent and safe power distribution among the battery cells.

[0033] In one possible embodiment, Figure 4 This is a flowchart of a battery power control method in a battery pack provided by an embodiment of the present disclosure. The method is applied to any one of the converters in the above embodiments and includes the following steps.

[0034] Step S410: Determine the first droop coefficient based on the current state of charge of the first battery cell connected in series.

[0035] In this embodiment, the first droop coefficient is mainly determined based on the current state of charge. In the discharge state, the larger the current state of charge, the smaller the first droop coefficient, so that battery cells with a larger current state of charge are discharged more in droop control, while the smaller the current state of charge, the larger the first droop coefficient, so that battery cells with a smaller current state of charge are discharged less in the discharge state. In the charging state, the larger the current state of charge, the larger the first droop coefficient, so that battery cells with a higher current state of charge are charged less in droop control, while the smaller the current state of charge, the smaller the first droop coefficient, so that battery cells with a smaller current state of charge are charged more in the charging state.

[0036] Step S420: Determine the second droop coefficient based on the current power limit of the first battery cell.

[0037] In this embodiment of the disclosure, the larger the current power limit, the smaller the second droop coefficient, which can enable battery cells with higher power limits to charge or discharge more in droop control. Conversely, the smaller the current power limit, the larger the second droop coefficient, which can enable battery cells with lower power limits to charge or discharge less in droop control.

[0038] Step S430: Determine the target droop coefficient of the first battery cell based on the first droop coefficient and the second droop coefficient.

[0039] In this embodiment of the disclosure, the correlation between the target droop coefficient and the first droop coefficient and the second droop coefficient can be such that when the operating power of each battery cell is much less than its respective power limit, the difference between the target droop coefficient and the first droop coefficient is less than a threshold, that is, close to the first droop coefficient; and when the operating power of at least one battery cell is close to its power limit, the difference between the target droop coefficient and the second droop coefficient is less than a threshold, that is, close to the second droop coefficient.

[0040] Step S440: Control the operating power of the first battery cell according to the target droop coefficient.

[0041] In this embodiment, the target droop coefficient can be determined by combining the state of charge and power limit. Then, based on the target droop coefficient, the operating power of the first battery cell can be controlled, so that the operating power of each battery cell can always be within its own safe power limit, thereby improving safety. Furthermore, while ensuring safety and battery pack lifespan, it can also maximize the instantaneous power change rate of the battery pack and improve overall utilization efficiency.

[0042] It should be noted that in this embodiment of the present disclosure, each converter in the battery pack can execute the battery power control method described above, and they can be executed in parallel to coordinately control the operating power of each battery cell in the battery pack.

[0043] The control method of the power converter according to the embodiments of this disclosure will be described in detail below.

[0044] Regarding the determination of the first droop coefficient based on the current state of charge of the first battery cell connected in series in step S410 above, this disclosure provides possible implementation methods.

[0045] 1) When the first battery cell is in a discharged state, a first droop coefficient is determined based on the current state of charge of the first battery cell connected in series. The first droop coefficient is negatively correlated with the current state of charge.

[0046] 2) When the first battery cell is in a charging state, a first droop coefficient is determined based on the current state of charge of the first battery cell connected in series. The first droop coefficient is positively correlated with the current state of charge.

[0047] In one possible embodiment, the current state of discharge or charging can be determined based on the output current of the first battery cell.

[0048] For example, obtaining the filtered value of the output current of the first battery cell. , A value less than 0 indicates a charging state, a value greater than 0 indicates a discharging state, and a value equal to 0 indicates a state of neither charging nor discharging. In this embodiment of the present disclosure, for ease of calculation, the case where the output current is equal to 0 is classified as the case greater than 0. Of course, it can also be classified as the case less than 0. This does not affect the calculation of the final target droop coefficient.

[0049] Among them, relevant parameters of the battery cell can be obtained in real time from the Battery Management System (BMS), such as real-time state of charge, real-time power limit, and current operating power.

[0050] The first droop coefficient is The first battery cell is denoted as the r-th battery cell, and the current state of charge of the r-th battery cell is denoted as... In the discharge state, the first droop coefficient is negatively correlated with the current state of charge, while in the charging state, the first droop coefficient is positively correlated with the current state of charge, as shown in the following formula.

[0051]

[0052] Since the first droop coefficient and the second droop coefficient are calculated based on different dimensions, their value ranges may differ significantly, which is not conducive to unified calculation. Therefore, in order to facilitate unified analysis and calculation of the first droop coefficient and the second droop coefficient in this embodiment of the disclosure, the first droop coefficient and the second droop coefficient can be normalized.

[0053] In one possible embodiment, the current state of charge of the first battery cell is normalized based on a preset first normalization calculation method to obtain a first droop coefficient.

[0054] For example, due to The range is 0~100%, in order to make Normalization to around 1 can be performed based on the current state of charge of the first battery cell and the current average state of charge of the battery pack. The current average state of charge is determined by averaging the current state of charge of each battery cell.

[0055] The first droop coefficient is The first battery cell is denoted as the r-th battery cell, and the current state of charge of the r-th battery cell is denoted as... The current average state of charge of the battery pack is expressed as The normalization calculation method for the first droop coefficient can be expressed as the following formula.

[0056]

[0057] Regarding the determination of the second droop coefficient based on the current power limit of the first battery cell in step S420, this disclosure provides a possible implementation method: the second droop coefficient is determined based on the current power limit of the first battery cell connected in series, and the second droop coefficient is negatively correlated with the current power limit.

[0058] For example, Representing the second droop coefficient, the current discharge power limit of the first battery cell can be expressed as: The current charging power limit is expressed as Then the second droop coefficient can be expressed as the following formula.

[0059]

[0060] Similarly, in this embodiment of the disclosure, the second droop coefficient can also be normalized. In one possible embodiment, the second droop coefficient is determined according to the current power limit of the first battery cell connected in series, including: normalizing the current power limit of the first battery cell according to a preset second normalization calculation method to obtain the second droop coefficient.

[0061] For example, in this embodiment of the disclosure, due to and The range is from 0 to the rated power. In order to normalize the second droop coefficient to around 1, normalization processing can be performed based on the current power limit of the first battery cell and the current average power limit of the battery pack to obtain the normalized second droop coefficient. The current average power limit can be the average of the current power limits of each battery cell or the harmonic mean, etc. It is preferable to choose the harmonic mean. This embodiment of the present disclosure does not limit this. In this way, the average can characterize the overall concentration trend of the battery power limit and is more sensitive to larger values, while the harmonic mean is more sensitive to smaller values ​​and can highlight the bottleneck part in the power limit.

[0062] For example, the current average discharge power limit is expressed as The current discharge power limit for each battery cell can be expressed as: If n represents the total number of battery cells in the battery pack, then the current average discharge power limit can be calculated using the following formula.

[0063]

[0064] The current average charging power limit is expressed as The current charging power limit for each battery cell can be expressed as: The current average charging power limit can be calculated using the following formula.

[0065]

[0066] For the r-th first battery cell, the normalized calculation formula for the second droop coefficient can be expressed as follows.

[0067]

[0068] In this embodiment of the disclosure, a second droop coefficient can be determined based on the ratio between the current average power limit and the current power limit, so that when the total operating power of the battery pack increases, each battery cell reaches its power limit as simultaneously as possible.

[0069] Regarding the step S430 above, in which the target droop coefficient of the first battery cell is determined based on the first droop coefficient and the second droop coefficient, this disclosure provides possible implementation methods:

[0070] Step S431: Determine the current power utilization rate of each battery cell based on its current operating power and current power limit.

[0071] For example, in this embodiment of the disclosure, the current power utilization rate can be obtained based on the ratio between the current operating power of each battery cell and the corresponding current power limit.

[0072] Step S432: Based on the current power utilization rate of each battery cell, determine the first weight value of the first droop coefficient and the second weight value of the second droop coefficient; wherein, the second weight value is positively correlated with the current power utilization rate of all battery cells, and the sum of the second weight value and the first weight value is a preset value.

[0073] For this step S432, this disclosure provides a possible implementation method: determine the first current power utilization rate with the largest value based on the current power utilization rate of all battery cells; determine the second weight value of the second droop coefficient based on the first current power utilization rate, the second weight value being positively correlated with the first current power utilization rate; and obtain the first weight value of the first droop coefficient based on the second weight value and a preset value.

[0074] For example, The second weight value can be calculated using the following formula.

[0075]

[0076]

[0077] in, and These are the current operating power and current discharge power limit of the first battery cell, respectively. and Similarly, by analogy, the ratio corresponding to each first battery cell can represent the difference between the current operating power and the current power limit, that is, it can represent the current power utilization rate. In this way, calculating the current power utilization rate of all battery cells in the battery pack and taking the maximum value among multiple current power utilization rates can be understood as taking the battery cell in the entire battery pack that is closest to the current power limit.

[0078] Right now This can represent the highest current power utilization rate, reflecting the maximum battery power load in the battery pack. This indicates that all battery cells are far from the power limit; if This indicates that at least one battery cell in the battery pack is close to full load; if This indicates that at least one battery cell in the battery pack has exceeded its power limit, and and They are positively correlated.

[0079] In one possible embodiment, as described in this disclosure, .

[0080] Through the Obtain by square amplitude calculation This can strengthen the Sensitivity close to 1, when When smaller, Smaller and more gradual, the droop factor design focuses more on the state of charge, when When it approaches 1, The rapid increase in power allows for a quick response to situations where a battery cell is about to reach full load. Of course, in this embodiment, the calculation method is not limited to the square magnitude; other powers can also be used for calculation, and there is no limitation on this.

[0081] In this embodiment of the disclosure, the calculation method for the second weight value of the charging state is similar to that of the discharging state described above, and will not be repeated here.

[0082] Then, based on the second weight value and the preset value, the first weight is calculated. For example, if the preset value is 1, the first weight value can be expressed as: .

[0083] Step S433: Obtain the first product between the first droop coefficient and the first weight value, and obtain the second product between the second droop coefficient and the second weight value.

[0084] Step S434: Obtain the target droop coefficient of the first battery cell by summing the first product and the second product.

[0085] For example, the target droop coefficient can be represented as k.

[0086]

[0087] in, The first droop coefficient, This is the second droop coefficient. As the second weighting value, based on the calculation method of the target droop coefficient mentioned above, it can be seen that when the operating power of each battery cell is much lower than its respective power limit, When the charge level approaches 0, the battery cells in the battery pack primarily distribute power according to their current state of charge. This occurs when at least one battery cell's operating power is close to its power limit. When the power value approaches 1, the battery cells in the battery pack mainly distribute power according to the current power limit. This can reduce the operating power of battery cells that are close to the power limit first, and ultimately achieve the goal of all battery cells reaching the power limit as simultaneously as possible.

[0088] Regarding the control of the operating power of the first battery cell based on the target droop coefficient in step S440 above, this disclosure also provides a possible implementation method, specifically: the operating power of the battery cell can be adjusted based on the set reference voltage, the target droop coefficient and the output current of the battery cell.

[0089] For example, as mentioned above Figure 2 The schematic diagram shown is as follows. For a stable battery pack system, the terminal voltages of all parallel battery cells will eventually converge.

[0090] Taking two battery cells connected in parallel as an example, the calculation of the reference voltage of the two battery cells can be expressed as follows.

[0091] ; .

[0092] In a steady state, for each battery cell, after dual closed-loop control, the actual bus voltage will equal its reference voltage. For example, for battery cell 1, it is... For battery cell 2, that is Since the two battery cells are connected in parallel on the same bus, then ,Right now , Therefore, the ratio of the current (i.e. the operating power) of the two battery cells can be adjusted by the target droop coefficient.

[0093] Based on the battery power control method in the battery pack of this disclosure, the current state of charge and current power limit of the battery cells in the battery pack can be combined to determine the target droop coefficient for droop control, and then the operating power of the battery cells can be controlled based on the target droop coefficient.

[0094] In one possible embodiment, see [reference] Figure 5 The diagram shown illustrates the relationship between the total power of the battery pack and the operating power of each battery cell in an embodiment of this disclosure. Taking a battery pack containing two battery cells as an example, assuming that the power limit of battery cell 1 is 4kW and the power limit of battery cell 2kW, as shown... Figure 5 As shown, the battery power control method in this embodiment can ensure that the operating power of each battery cell is within its own power limit, avoiding the occurrence of a certain battery cell working at its power limit for a long time, which can improve system safety and maximize the instantaneous power change rate of the battery pack system, thereby improving overall utilization efficiency.

[0095] It is understood that the various method embodiments mentioned above in this disclosure can be combined with each other to form combined embodiments without violating the principle and logic. Due to space limitations, this disclosure will not elaborate further. Those skilled in the art will understand that in the above methods of specific implementation, the specific execution order of each step should be determined by its function and possible internal logic.

[0096] In addition, this disclosure also provides a battery power control system, converter, electronic device, computer-readable storage medium, and computer program product for a battery pack. All of the above can be used to implement any of the battery power control methods for a battery pack provided in this disclosure. The corresponding technical solutions and descriptions are described in the corresponding section of the method and will not be repeated here.

[0097] This disclosure provides a converter, which is any one of the converters in a battery pack. The battery pack includes at least two battery cells and at least two converters. Each battery cell is connected in series with a converter to form a branch, and different branches are connected in parallel. The converter is used to: determine a first droop coefficient based on the current state of charge of the first battery cell connected in series; determine a second droop coefficient based on the current power limit of the first battery cell; determine a target droop coefficient of the first battery cell based on the first droop coefficient and the second droop coefficient; and control the operating power of the first battery cell based on the target droop coefficient.

[0098] Figure 6 This is a block diagram of a battery power control system in a battery pack, provided as an embodiment of the present disclosure.

[0099] Reference Figure 6 This disclosure provides a battery power control system for a battery pack. The system includes a battery pack 610 and a host 620. The battery pack 610 includes at least two battery cells 611 and at least two converters 612. Each battery cell 611 is connected in series with a converter 612 to form a branch. Different branches are connected in parallel. The host 620 is communicatively connected to each converter 612. The converter 612 is used to execute the battery power control method in the battery pack in the above embodiment.

[0100] In this embodiment of the disclosure, the host can be any one of multiple converters. One of the converters can be pre-configured as the host, or a separate electronic device can be set as the host. This embodiment of the disclosure does not impose any restrictions on this.

[0101] In this embodiment of the disclosure, such as Figure 6As shown, each converter 612 can communicate with the host 620. Each converter 612 can be understood as a slave of the host 620. Each converter 612 can send the operating power, current state of charge, current discharge power limit, and current charging power limit of the connected battery cells to the host 620. Then, the host 620 can calculate the current average state of charge, current average discharge power limit, current average charging power limit, and second weight value of the battery pack based on these data, and send them to each converter 612. Thus, each converter 612 can determine the target droop coefficient of its series-connected battery cells based on the battery power control method in the battery pack of this embodiment, so as to control the operating power of the battery cells.

[0102] Figure 7 This is a block diagram of an electronic device provided in an embodiment of the present disclosure.

[0103] Reference Figure 7 This disclosure provides an electronic device, which includes: at least one processor 701; at least one memory 702; and one or more I / O interfaces 703; wherein the memory 702 stores one or more computer programs that can be executed by at least one processor 701, and the one or more computer programs are executed by at least one processor 701 to enable at least one processor 701 to execute the battery power control method in the battery pack described above.

[0104] This disclosure also provides a computer-readable storage medium storing a computer program thereon, wherein the computer program, when executed by a processor, implements the battery power control method in the battery pack described above. The computer-readable storage medium may be volatile or non-volatile.

[0105] This disclosure also provides a computer program product, including computer-readable code, or a non-volatile computer-readable storage medium carrying computer-readable code, wherein when the computer-readable code is run in a processor of an electronic device, the processor in the electronic device executes the battery power control method in the battery pack described above.

[0106] Those skilled in the art will understand that all or some of the steps, systems, and apparatuses disclosed above, and their functional modules / units, can be implemented as software, firmware, hardware, or suitable combinations thereof. In hardware implementations, the division between functional modules / units mentioned above does not necessarily correspond to the division of physical components; for example, a physical component may have multiple functions, or a function or step may be performed collaboratively by several physical components. Some or all physical components may be implemented as software executed by a processor, such as a central processing unit, digital signal processor, or microprocessor, or as hardware, or as an integrated circuit, such as an application-specific integrated circuit (ASIC). Such software can be distributed on a computer-readable storage medium, which may include computer storage media (or non-transitory media) and communication media (or transient media).

[0107] As is known to those skilled in the art, the term computer storage medium includes volatile and non-volatile, removable and non-removable media implemented in any method or technology for storing information, such as computer-readable program instructions, data structures, program modules, or other data. Computer storage media includes, but is not limited to, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM), static random-access memory (SRAM), flash memory or other memory technologies, compact disc read-only memory (CD-ROM), digital versatile disc (DVD) or other optical disc storage, magnetic cartridges, magnetic tapes, disk storage or other magnetic storage devices, or any other medium that can be used to store desired information and is accessible to a computer. Furthermore, it is known to those skilled in the art that communication media typically contain computer-readable program instructions, data structures, program modules, or other data in modulated data signals such as carrier waves or other transmission mechanisms, and may include any information delivery medium.

[0108] The computer-readable program instructions described herein can be downloaded from computer-readable storage media to various computing / processing devices, or downloaded via a network, such as the Internet, local area network, wide area network, and / or wireless network, to an external computer or external storage device. The network may include copper transmission cables, fiber optic transmission, wireless transmission, routers, firewalls, switches, gateway computers, and / or edge servers. A network adapter card or network interface in each computing / processing device receives the computer-readable program instructions from the network and forwards them to the computer-readable storage media in the respective computing / processing device.

[0109] Computer program instructions used to perform the operations of this disclosure may be assembly instructions, instruction set architecture (ISA) instructions, machine instructions, microcode, firmware instructions, state setting data, or source code or object code written in any combination of one or more programming languages, including object-oriented programming languages ​​such as Smalltalk, C++, etc., and conventional procedural programming languages ​​such as the "C" language or similar programming languages. The computer-readable program instructions may execute entirely on the user's computer, partially on the user's computer, as a standalone software package, partially on the user's computer and partially on a remote computer, or entirely on a remote computer or server. In cases involving a remote computer, the remote computer may be connected to the user's computer via any type of network—including a local area network (LAN) or a wide area network (WAN), or may be connected to an external computer (e.g., via the Internet using an Internet service provider). In some embodiments, electronic circuitry, such as programmable logic circuitry, field-programmable gate arrays (FPGAs), or programmable logic arrays, may execute computer-readable program instructions to implement various aspects of this disclosure by utilizing state information from the computer-readable program instructions.

[0110] The computer program product described herein can be implemented specifically through hardware, software, or a combination thereof. In one alternative embodiment, the computer program product is specifically embodied in a computer storage medium; in another alternative embodiment, the computer program product is specifically embodied in a software product, such as a software development kit (SDK), etc.

[0111] Various aspects of this disclosure are described herein with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of this disclosure. It should be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer-readable program instructions.

[0112] These computer-readable program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, or other programmable data processing apparatus to produce a machine such that, when executed by the processor of the computer or other programmable data processing apparatus, they create means for implementing the functions / actions specified in one or more blocks of the flowchart and / or block diagram. These computer-readable program instructions can also be stored in a computer-readable storage medium that causes a computer, programmable data processing apparatus, and / or other device to operate in a particular manner; thus, the computer-readable medium storing the instructions comprises an article of manufacture that includes instructions for implementing aspects of the functions / actions specified in one or more blocks of the flowchart and / or block diagram.

[0113] Computer-readable program instructions may also be loaded onto a computer, other programmable data processing apparatus, or other device to cause a series of operational steps to be performed on the computer, other programmable data processing apparatus, or other device to produce a computer-implemented process, thereby causing the instructions executed on the computer, other programmable data processing apparatus, or other device to perform the functions / actions specified in one or more boxes of a flowchart and / or block diagram.

[0114] 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 the present disclosure. In this regard, each block in a flowchart or block diagram may represent a module, segment, or portion of an instruction containing one or more executable instructions for implementing a specified logical function. In some alternative implementations, the functions marked in the blocks may occur in a different order than those shown in the drawings. For example, two consecutive 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 the block diagrams and / or flowcharts, and combinations of blocks in the block diagrams and / or flowcharts, may be implemented using a dedicated hardware-based system that performs the specified function or action, or using a combination of dedicated hardware and computer instructions.

[0115] Example embodiments have been disclosed herein, and while specific terminology has been used, it is for illustrative purposes only and should be construed as such, and is not intended to be limiting. In some instances, it will be apparent to those skilled in the art that features, characteristics, and / or elements described in connection with particular embodiments may be used alone, or in combination with features, characteristics, and / or elements described in connection with other embodiments, unless otherwise expressly indicated. Therefore, those skilled in the art will understand that various changes in form and detail may be made without departing from the scope of this disclosure as set forth by the appended claims.

Claims

1. A battery power control method in a battery pack, characterized in that, The battery pack includes at least two battery cells and at least two converters. Each battery cell is connected in series with a converter to form a branch, and different branches are connected in parallel. The method is applied to any one of the converters, and the method includes: The first droop coefficient is determined based on the current state of charge of the first battery cell connected in series. The second droop coefficient is determined based on the current power limit of the first battery cell; The target droop coefficient of the first battery cell is determined based on the first droop coefficient and the second droop coefficient. The operating power of the first battery cell is controlled according to the target droop coefficient. The step of determining the target droop coefficient of the first battery cell based on the first droop coefficient and the second droop coefficient includes: determining the current power utilization rate of each battery cell based on the current operating power and current power limit of each battery cell; determining a first weight value of the first droop coefficient and a second weight value of the second droop coefficient based on the current power utilization rate of each battery cell; wherein the second weight value is positively correlated with the current power utilization rate of all battery cells, and the sum of the second weight value and the first weight value is a preset value; obtaining a first product between the first droop coefficient and the first weight value, and obtaining a second product between the second droop coefficient and the second weight value; and obtaining the target droop coefficient of the first battery cell based on the sum of the first product and the second product.

2. The method according to claim 1, characterized in that, The step of determining a first weight value for the first droop coefficient and a second weight value for the second droop coefficient based on the current power utilization rate of each battery cell includes: Based on the current power utilization rate of all the battery cells, determine the first current power utilization rate with the largest value; Based on the first current power utilization rate, a second weight value for the second droop coefficient is determined, and the second weight value is positively correlated with the first current power utilization rate. Based on the second weight value and the preset value, the first weight value of the first droop coefficient is obtained.

3. The method according to claim 1, characterized in that, Determining the first droop coefficient based on the current state of charge of the first battery cell connected in series includes: When the first battery cell is in a discharging state, a first droop coefficient is determined based on the current state of charge of the first battery cell connected in series. The first droop coefficient is negatively correlated with the current state of charge. When the first battery cell is in a charging state, a first droop coefficient is determined based on the current state of charge of the first battery cell connected in series. The first droop coefficient is positively correlated with the current state of charge.

4. The method according to claim 3, characterized in that, Determining the first droop coefficient based on the current state of charge of the first battery cell connected in series includes: Based on a preset first normalization calculation method, the current state of charge of the first battery cell is normalized to obtain a first droop coefficient.

5. The method according to claim 1, characterized in that, Determining the second droop coefficient based on the current power limit of the first battery cell includes: A second droop coefficient is determined based on the current power limit of the first battery cell connected in series, and the second droop coefficient is negatively correlated with the current power limit.

6. The method according to claim 5, characterized in that, The step of determining the second droop coefficient based on the current power limit of the first battery cell connected in series includes: According to the preset second normalization calculation method, the current power limit of the first battery cell is normalized to obtain the second droop coefficient.

7. A converter, characterized in that, The converter is any one of the battery packs, which includes at least two battery cells and at least two converters. Each battery cell is connected in series with one converter to form a branch, and different branches are connected in parallel. The converter is used for: The first droop coefficient is determined based on the current state of charge of the first battery cell connected in series. The second droop coefficient is determined based on the current power limit of the first battery cell; The target droop coefficient of the first battery cell is determined based on the first droop coefficient and the second droop coefficient. The operating power of the first battery cell is controlled according to the target droop coefficient. The step of determining the target droop coefficient of the first battery cell based on the first droop coefficient and the second droop coefficient includes: determining the current power utilization rate of each battery cell based on the current operating power and current power limit of each battery cell; determining a first weight value of the first droop coefficient and a second weight value of the second droop coefficient based on the current power utilization rate of each battery cell; wherein the second weight value is positively correlated with the current power utilization rate of all battery cells, and the sum of the second weight value and the first weight value is a preset value; obtaining a first product between the first droop coefficient and the first weight value, and obtaining a second product between the second droop coefficient and the second weight value; and obtaining the target droop coefficient of the first battery cell based on the sum of the first product and the second product.

8. A battery power control system for a battery pack, characterized in that, include: The battery pack and the host are provided. The battery pack includes at least two battery cells and at least two converters. Each battery cell is connected in series with one of the converters to form a branch. Different branches are connected in parallel. The host communicates with each of the converters. The converters are used to execute the battery power control method in the battery pack as described in any one of claims 1-6.

9. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by the processor, it implements the battery power control method in the battery pack as described in any one of claims 1-6.

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