Battery pack offline equalization method, energy storage device, electronic equipment and storage medium

Abstract

The invention discloses a battery pack offline balancing method, an energy storage device, electronic equipment and a storage medium. The battery pack off-line equalization method comprises the following steps: acquiring the optimal temperature rise rate of current equalization, the awakening times of the main control board and the duty ratio of the previous equalization; if the awakening frequency of the main control board is equal to zero, taking the online temperature rise rate during online equalization as the previous equalization temperature rise rate; if the awakening frequency of the main control board is greater than zero, taking the equalization temperature rise rate during the previous offline equalization as the previous equalization temperature rise rate; calculating the current equalization duty ratio according to the current equalization optimal temperature rise rate, the previous equalization temperature rise rate and the previous equalization duty ratio; and balancing the battery pack according to the current balancing duty ratio. According to the embodiment of the invention, the equalization duty ratio in the off-line equalization period can be adjusted according to the optimal temperature rise rate of the current equalization and the temperature rise rate of the previous equalization, so that the time ratio for equalization in the off-line equalization period is improved, and the equalization efficiency of off-line equalization of the battery pack is improved.

Description

Technical Field

[0001] This invention relates to the field of battery pack technology, and more particularly to offline battery pack balancing methods, energy storage devices, electronic devices, and storage media. Background Technology

[0002] A battery pack is typically composed of multiple cells connected in series and parallel. Differences in internal resistance and self-discharge among the cells result in charge differences between them, affecting the overall performance of the battery pack. An on-board power battery system includes the battery pack and the battery management system. Currently, most on-board power battery packs employ passive balancing, where the battery management system uses the heat generated by resistors to dissipate the energy of high-charge cells, thus maintaining the consistency of the cells within the pack. Existing online balancing solutions can only be activated when the vehicle is awakened; however, relying solely on balancing during vehicle use is ineffective and cannot significantly improve the overall battery pack capacity.

[0003] Based on this, the industry has begun to adopt an offline balancing solution, in which the main control board of the battery management system sends the balancing command to the slave control board in advance, and then the main control board goes into sleep mode, while the slave control board continues to perform the balancing by being powered by the battery.

[0004] However, in the prior art, the equalization duty cycle of the battery pack is fixed during offline equalization, which also results in low equalization efficiency of the battery pack during offline equalization. Summary of the Invention

[0005] This invention provides a battery pack offline balancing method, an energy storage device, an electronic device, and a storage medium to improve the balancing efficiency of battery pack offline balancing.

[0006] According to one aspect of the present invention, a battery pack offline balancing method is provided, wherein the main control board calculates the duty cycle of the battery pack for this balancing operation before the start of the current balancing operation and goes into sleep mode during the current offline balancing operation; the slave control board performs balancing on the battery pack according to the current balancing duty cycle; the battery pack offline balancing method includes:

[0007] The optimal temperature rise rate for this equalization, the number of times the main control board is woken up this time, and the duty cycle of the previous equalization are obtained; wherein, the optimal temperature rise rate for this equalization is the average temperature rise rate from the current temperature to the maximum allowable temperature of the control board during the remaining offline equalization time; and the duty cycle of the previous equalization is the equalization duty cycle during the previous equalization.

[0008] If the number of wake-ups of the main control board is zero, the online temperature rise rate during online balancing will be used as the temperature rise rate of the previous balancing; wherein, the online temperature rise rate is the temperature rise rate of the slave control board calculated last time before the battery pack is offline balanced.

[0009] If the number of wake-ups of the main control board is greater than zero, then the temperature rise rate during the previous offline balancing is taken as the previous temperature rise rate.

[0010] The current equilibrium duty cycle is calculated based on the current equilibrium optimal temperature rise rate, the previous equilibrium temperature rise rate, and the previous equilibrium duty cycle.

[0011] The battery pack is balanced according to the aforementioned balance duty cycle.

[0012] Optionally, specific methods for obtaining the equilibrium temperature rise rate during the previous offline equilibrium include:

[0013] Get the slave control board temperature before the previous offline equalization, the slave control board temperature after the previous offline equalization, and the time of the previous offline equalization.

[0014] The temperature difference is calculated based on the slave control board temperature before the previous offline equalization and the slave control board temperature after the previous offline equalization.

[0015] The equilibrium temperature rise rate during the previous offline equilibrium is calculated based on the temperature difference and the previous offline equilibrium time.

[0016] Optionally, specific methods for obtaining the optimal temperature rise rate for this equilibrium include:

[0017] Obtain the current maximum slave control board temperature, the maximum allowable temperature, and the remaining offline equalization time; wherein, the current maximum slave control board temperature is the temperature of the slave control board with the highest temperature at the current moment;

[0018] Calculate the maximum temperature difference based on the current maximum slave control board temperature and the maximum allowable temperature;

[0019] The optimal temperature rise rate for this equilibrium is calculated based on the maximum temperature difference and the remaining offline equilibrium time.

[0020] Optionally, the specific method for obtaining the remaining offline balancing time includes:

[0021] Obtain the total offline balancing time and the offline balancing duration; wherein, the offline balancing duration is the time interval between the offline balancing start time and the current time;

[0022] The remaining offline balancing time is calculated based on the total offline balancing time and the offline balancing duration.

[0023] Optionally, the time interval between each wake-up of the main control board is equal; specific methods for obtaining the offline balancing time include:

[0024] Get the wake-up interval of the main control board;

[0025] The offline balancing time is calculated based on the number of times the main control board is woken up and the wake-up interval.

[0026] Optionally, the battery management system includes a main control board and at least one slave control board; before obtaining the optimal temperature rise rate for this equalization, the number of times the main control board is woken up this time, and the duty cycle of the previous equalization, it further includes:

[0027] Obtain the fault level of the battery management system, battery pack capacity, maximum slave control board temperature, and individual cell capacity difference;

[0028] If the fault level of the battery management system is less than the preset level, the battery pack capacity is greater than the preset capacity threshold, the maximum slave control board temperature is less than the protection threshold, and the individual cell capacity difference is greater than the activation threshold, then obtain the optimal temperature rise rate for this equalization, the number of times the main control board is woken up this time, and the duty cycle of the previous equalization.

[0029] If the fault level of the battery management system is greater than or equal to a preset level, the battery pack charge is less than or equal to a preset charge threshold, the maximum slave control board temperature is greater than or equal to a protection threshold, or the charge difference of a single cell is less than or equal to an activation threshold, then the battery pack is controlled to enter sleep mode.

[0030] Optionally, after equalizing the battery pack according to the current equalization duty cycle, the method further includes:

[0031] Get the maximum slave board temperature at the current moment;

[0032] If the maximum slave board temperature at the current moment is greater than the maximum allowable temperature, then the equalization process is stopped and the master board is woken up.

[0033] According to another aspect of the present invention, an energy storage device is also provided, the energy storage device comprising a main control board, a battery pack and at least one slave control board;

[0034] The slave control board is connected to the battery pack; the slave control board is also connected to the main control board;

[0035] The battery pack is used to store electrical energy; the main control board and each of the slave control boards are used to execute the battery pack offline balancing method described in any of the above embodiments.

[0036] According to another aspect of the present invention, an electronic device is also provided, the electronic device comprising:

[0037] At least one processor; and

[0038] A memory communicatively connected to the at least one processor; wherein,

[0039] The memory stores a computer program that can be executed by the at least one processor, which enables the at least one processor to perform the battery pack offline balancing method described in any of the above embodiments.

[0040] According to another aspect of the present invention, a computer-readable storage medium is also provided, the computer-readable storage medium storing computer instructions for causing a processor to execute and implement the battery pack offline balancing method described in any of the above embodiments.

[0041] This invention, in its embodiments, obtains the previous equalization temperature rise rate based on the number of times the main control board is woken up, and corrects the previous equalization duty cycle based on the current optimal equalization temperature rise rate and the previous equalization temperature rise rate to obtain the current equalization duty cycle. This ensures that the slave control board temperature never exceeds the maximum allowable temperature during offline equalization. Compared with the prior art, this invention can adjust the equalization duty cycle during offline equalization based on the current optimal equalization temperature rise rate and the previous equalization temperature rise rate, thereby increasing the proportion of time dedicated to equalization during offline equalization and improving the equalization efficiency of battery pack offline equalization.

[0042] It should be understood that the description in this section is not intended to identify key or essential features of the embodiments of the present invention, nor is it intended to limit the scope of the invention. Other features of the invention will become readily apparent from the following description. Attached Figure Description

[0043] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0044] Figure 1 This is a flowchart of an offline battery pack balancing method provided in Embodiment 1 of the present invention;

[0045] Figure 2 This is a flowchart of a method for obtaining the equalization temperature rise rate during the previous offline equalization, provided in Embodiment 2 of the present invention;

[0046] Figure 3 This is a flowchart of a method for obtaining the optimal temperature rise rate in this equilibrium process, provided in Embodiment 3 of the present invention.

[0047] Figure 4 This is a flowchart of an offline battery pack balancing method provided in Embodiment 4 of the present invention;

[0048] Figure 5This is a schematic diagram of an energy storage device provided in Embodiment 5 of the present invention;

[0049] Figure 6 This is a schematic diagram of the structure of an electronic device provided in Embodiment Six of the present invention. Detailed Implementation

[0050] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of the present invention.

[0051] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this invention are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of the invention described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover a non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0052] Example 1

[0053] Figure 1 This is a flowchart of an offline battery pack balancing method provided in Embodiment 1 of the present invention. This offline battery pack balancing method is applicable to balancing the battery pack of an electrical device when it is not in operation. The method can be executed by a battery management system, which includes a main control board and slave control boards. The battery management system can be implemented by software and / or hardware. Before the start of this balancing operation, the main control board calculates the duty cycle of the battery pack for this balancing operation and goes into sleep mode during this offline balancing period. The slave control board balances the battery pack according to the duty cycle of this balancing operation. The period from the start of sleep mode to the main control board being woken up constitutes one balancing operation. The offline balancing of the battery pack includes multiple balancing operations.

[0054] The following describes the offline battery pack balancing method. (Refer to...) Figure 1 The offline equalization method for the battery pack includes:

[0055] S110. Obtain the optimal temperature rise rate for this equalization, the number of times the main control board is woken up this time, and the duty cycle of the previous equalization; wherein, the optimal temperature rise rate for this equalization is the average temperature rise rate from the current temperature to the maximum allowable temperature of the control board during the remaining offline equalization time; the duty cycle of the previous equalization is the equalization duty cycle during the previous equalization.

[0056] Specifically, the optimal temperature rise rate for this equalization represents the ideal temperature rise rate of the slave control board during the remaining offline equalization time. This optimal temperature rise rate can be calculated based on the current temperature and maximum allowable temperature of the slave control board. The previous equalization duty cycle is the equalization duty cycle during the last equalization operation, and this parameter provides an important reference for the current equalization operation. Specifically, the previous equalization duty cycle is the equalization duty cycle of the battery pack during the last equalization. If the previous equalization of the battery pack was online, the online equalization duty cycle is used as the previous equalization duty cycle; if the previous equalization of the battery pack was offline, the duty cycle of the previous offline equalization is used as the previous equalization duty cycle. The number of times the main control board is woken up this time is the number of times the main control board has been woken up from the start of offline equalization to the current time. The number of times the main control board wakes up is a non-negative integer. The duration of each sleep cycle of the main control board can be set according to the actual situation. It can be a sleep cycle of equal duration or unequal duration. In other words, the time interval between each wake-up of the main control board can be equal or unequal. This embodiment does not impose any restrictions on this.

[0057] S120. Determine if the number of wake-up attempts of the main control board this time is greater than zero; if yes, execute S130; if no, execute S140.

[0058] Specifically, when the number of wake-ups by the main control board is greater than zero, it indicates that the current equalization of the battery pack is not the first equalization during the current offline equalization period. In this case, the equalization temperature rise rate of the battery pack during the previous offline equalization is obtained and used as the previous equalization temperature rise rate. When the number of wake-ups by the main control board is equal to zero, it indicates that the current equalization of the battery pack is the first equalization during the current offline equalization period. In this case, the online temperature rise rate of the battery pack during online equalization is obtained and used as the previous equalization temperature rise rate.

[0059] S130, Use the previous offline balancing temperature rise rate as the previous balancing temperature rise rate.

[0060] Specifically, the equalization temperature rise rate during the previous offline equalization of the battery pack indicates the average rate of temperature rise of the control board during the previous offline equalization of the battery pack, which reflects the temperature change of the control board during the previous offline equalization of the battery pack.

[0061] S140. The online temperature rise rate during online balancing is taken as the temperature rise rate of the previous balancing; wherein, the online temperature rise rate is the temperature rise rate of the slave control board calculated last time before the battery pack offline balancing.

[0062] Specifically, when the electrical equipment is operating, the battery management system continuously balances the battery pack, that is, it performs online balancing of the battery pack. During this time, both the main control board and the slave control board of the battery management system are online. During the online balancing of the battery pack, the battery management system calculates the temperature rise rate of the slave control board at regular intervals, that is, it calculates the online temperature rise rate at regular intervals. It should be noted that the interval between every two online temperature rise rate calculations during the online balancing of the battery pack can be set according to actual needs, and this embodiment does not impose any restrictions on this.

[0063] S150. Calculate the current equilibrium duty cycle based on the current equilibrium optimal temperature rise rate, the previous equilibrium temperature rise rate, and the previous equilibrium duty cycle.

[0064] Specifically, the current equalization duty cycle is the duty cycle of the battery pack during the remaining offline equalization time. The main control board is woken up multiple times during the entire offline equalization period of the battery pack, and calculates the current equalization duty cycle during each wake-up. The current equalization duty cycle is essentially a correction of the previous equalization duty cycle based on the previous equalization temperature rise rate and the optimal temperature rise rate for this equalization, ensuring that the slave control board temperature never exceeds the maximum allowable temperature during the remaining offline equalization time. The current equalization duty cycle can be calculated using the following formula:

[0065] Duty cal =Rate best ÷Rate old ×Duty old ;

[0066] Among them, Duty cal This is the equilibrium duty cycle; Rate best The optimal temperature rise rate for this equilibrium; Rate old The previous equilibrium temperature rise rate; Duty old This represents the duty cycle of the previous equilibrium.

[0067] S160. Equalize the battery pack according to the current equalization duty cycle.

[0068] Specifically, the current balancing duty cycle is obtained from the control board, and the battery pack is balanced based on this duty cycle until the main control board wakes up again. It should be noted that when the current balancing duty cycle is obtained from the control board, the main control board immediately enters sleep mode.

[0069] This invention, in its embodiments, obtains the previous equalization temperature rise rate based on the number of times the main control board is woken up, and corrects the previous equalization duty cycle based on the current optimal equalization temperature rise rate and the previous equalization temperature rise rate to obtain the current equalization duty cycle. This ensures that the slave control board temperature never exceeds the maximum allowable temperature during offline equalization. Compared with the prior art, this invention can adjust the equalization duty cycle during offline equalization based on the current optimal equalization temperature rise rate and the previous equalization temperature rise rate, thereby increasing the proportion of time dedicated to equalization during offline equalization and improving the equalization efficiency of battery pack offline equalization.

[0070] Example 2

[0071] Figure 2 This is a flowchart of a method for obtaining the equalization temperature rise rate during the previous offline equalization, provided in Embodiment 2 of the present invention. When using the equalization temperature rise rate during the previous offline equalization as the previous equalization temperature rise rate, the equalization temperature rise rate during the previous offline equalization should be obtained.

[0072] In this embodiment, obtaining the equalization temperature rise rate during the previous offline equalization is further specified as follows: obtaining the slave control board temperature before the previous offline equalization, the slave control board temperature after the previous offline equalization, and the previous offline equalization time; calculating the temperature difference based on the slave control board temperature before and after the previous offline equalization; and calculating the equalization temperature rise rate during the previous offline equalization based on the temperature difference and the previous offline equalization time. For details not covered in this embodiment, please refer to Embodiment 1.

[0073] Based on the above embodiments, optionally, refer to Figure 2 The specific method for obtaining the equilibrium temperature rise rate during the previous offline equilibrium includes the following steps:

[0074] S131. Obtain the slave control board temperature before the previous offline equalization, the slave control board temperature after the previous offline equalization, and the time of the previous offline equalization.

[0075] Specifically, the slave control board temperature before the previous offline equalization reflects the slave control board temperature at the start of the previous equalization during this offline equalization period. The slave control board temperature after the previous offline equalization reflects the slave control board temperature at the end of the previous equalization during this offline equalization period. The previous offline equalization time is the duration between the start time of the last sleep cycle on the main control board and the wake-up time of the current main control board. Optionally, before each equalization cycle during the offline equalization period, i.e. before the main control board goes into sleep, the main control board can acquire and record the current temperature of the slave control board. Since the main control board only calculates the duty cycle for this equalization cycle when it wakes up, the wake-up time is short, and the temperature change of the slave control board is small during this period. Therefore, the current temperature of the slave control board can be equivalent to the slave control board temperature after the previous offline equalization.

[0076] S132. Calculate the temperature difference based on the slave control board temperature before the previous offline equalization and the slave control board temperature after the previous offline equalization.

[0077] Specifically, the temperature difference between the slave control board temperature before the previous offline equalization and the slave control board temperature after the previous offline equalization represents the temperature change of the slave control board of the battery pack during the previous equalization in this offline equalization period.

[0078] S133. Calculate the equilibrium temperature rise rate during the previous offline equilibrium based on the temperature difference and the previous offline equilibrium time.

[0079] Specifically, the equalization temperature rise rate during the previous offline equalization characterizes the rate at which the battery pack's slave control board temperature changes during the current offline equalization, reflecting the heat generation of the slave control board during the equalization process. The equalization temperature rise rate during the previous offline equalization can be calculated by combining the temperature difference between the slave control board temperature before and after the previous offline equalization with the previous offline equalization time.

[0080] Embodiment 2 of the present invention specifies a method for obtaining the equilibrium temperature rise rate during the previous offline equilibrium. This method can be used to calculate the equilibrium temperature rise rate during the previous offline equilibrium, providing a foundation for calculating the duty cycle of the current equilibrium.

[0081] Example 3

[0082] Figure 3 This is a flowchart of a method for obtaining the optimal temperature rise rate for this equalization process, provided in Embodiment 3 of the present invention. In this embodiment, obtaining the optimal temperature rise rate for this equalization process is further specified as follows: obtaining the current maximum slave control board temperature, the maximum allowable temperature, and the remaining offline equalization time; wherein, the current maximum slave control board temperature is the temperature of the slave control board with the highest temperature at the current moment; calculating the maximum temperature difference based on the current maximum slave control board temperature and the maximum allowable temperature; and calculating the optimal temperature rise rate for this equalization process based on the maximum temperature difference and the remaining offline equalization time. For details not covered in this embodiment, please refer to Embodiment 1.

[0083] Based on the above embodiments, optionally, refer to Figure 3 The specific methods for obtaining the optimal temperature rise rate for this equilibrium include:

[0084] S111. Obtain the current maximum slave board temperature, the maximum allowable temperature, and the remaining offline balancing time; where the current maximum slave board temperature is the temperature of the slave board with the highest temperature at the current moment.

[0085] Specifically, the current maximum slave control board temperature is the temperature of the slave control board with the highest temperature in the battery management system. The maximum allowable temperature is the maximum temperature that the slave control board is allowed to reach during battery pack balancing. The remaining offline balancing time is the time remaining until the end of the offline balancing process. The remaining offline balancing time can be calculated based on the total offline balancing time and the elapsed offline balancing time. It should be noted that the total offline balancing time is a preset total offline balancing time for the battery pack, which can be set according to actual needs; this embodiment does not impose any restrictions on this.

[0086] The offline balancing duration is the time between the start time of the battery pack offline balancing and the current time. The offline balancing duration can be calculated from the time interval between each wake-up of the main control board up to the current time. The time interval between each wake-up of the main control board can be set according to actual needs; this embodiment does not impose any restrictions on this. When the time interval between each wake-up of the main control board is equal, the offline balancing duration can be calculated based on the wake-up interval of the main control board and the number of wake-ups in this instance.

[0087] S112. Calculate the maximum temperature difference based on the current maximum slave control board temperature and the maximum allowable temperature.

[0088] Specifically, the maximum temperature difference characterizes the temperature difference between the current maximum slave board temperature and the maximum allowable temperature, reflecting the maximum temperature variation allowed by the slave board.

[0089] S113. Calculate the optimal temperature rise rate for this equilibrium based on the maximum temperature difference and the remaining offline equilibrium time.

[0090] Specifically, the optimal temperature rise rate in this equalization process characterizes the ideal temperature change of the slave control board during the remaining offline equalization time, reflecting the ideal heat generation of the slave control board during this period. The optimal temperature rise rate can be calculated by combining the maximum temperature difference between the current maximum slave control board temperature and the maximum allowable temperature with the remaining offline equalization time.

[0091] Embodiment 3 of the present invention specifies a method for obtaining the optimal temperature rise rate for this equilibrium. This method can be used to calculate the optimal temperature rise rate for this equilibrium, providing a foundation for subsequent calculations of the duty cycle for this equilibrium.

[0092] Example 4

[0093] Figure 4 This is a flowchart of a battery pack offline balancing method provided in Embodiment 4 of the present invention. The battery management system includes a main control board and at least one slave control board. This embodiment specifically describes the conditions for enabling battery pack offline balancing and the detection of battery pack balancing anomalies.

[0094] Based on the above embodiments, optionally, refer to Figure 4 Before obtaining the optimal temperature rise rate for this equalization, the number of times the main control board wakes up this time, and the duty cycle of the previous equalization, the following steps are also included:

[0095] S210: Obtain the fault level of the battery management system, battery pack capacity, maximum slave control board temperature, and individual cell capacity difference.

[0096] Specifically, before offline equalization, the battery management system performs a self-check and assesses its own fault level. Battery pack capacity and maximum slave control board temperature can be obtained through slave control board detection. The individual cell capacity difference is the difference between the cell with the highest capacity and the cell with the lowest capacity in the battery pack. The individual cell capacity can be obtained through slave control board detection.

[0097] S220: Determine whether the fault level of the battery management system is less than the preset level, whether the battery pack capacity is greater than the preset capacity threshold, whether the maximum slave control board temperature is less than the protection threshold, and whether the individual cell capacity difference is greater than the activation threshold; if yes, execute S110; if no, execute S230.

[0098] Specifically, the preset level is a pre-set fault level that does not affect the battery pack's offline balancing. When the fault level of the battery management system is less than the preset level, it indicates that the fault in the battery management system has no impact on the battery pack's offline balancing, and the battery pack can perform offline balancing. When the fault level of the battery management system is greater than or equal to the preset level, it indicates that the fault in the battery management system will affect the battery pack's offline balancing, and the battery pack's offline balancing is disabled. The preset power threshold is a pre-set battery power threshold value for the battery pack's offline balancing. The protection threshold is a pre-set slave control board temperature threshold value for the battery pack's offline balancing. The individual cell power difference is a pre-set cell power difference value for enabling the battery pack's offline balancing. The battery pack can enable balancing only when the fault level of the battery management system is less than the preset level, the battery pack power is greater than the preset power threshold, the maximum slave control board temperature is less than the protection threshold, and the individual cell power difference is greater than the activation threshold. In this case, S110 is executed to obtain the optimal temperature rise rate for this balancing, the number of times the main control board wakes up this time, and the duty cycle of the previous balancing; otherwise, S230 is executed to control the battery pack to hibernate.

[0099] S230, controls battery pack hibernation.

[0100] Based on the above embodiments, optionally, refer to... Figure 4 After balancing the battery pack according to the current balancing duty cycle, the process also includes:

[0101] S170, Obtain the maximum slave board temperature at the current moment.

[0102] Specifically, the maximum slave control board temperature at the current moment is the temperature of the slave control board with the highest temperature inside the battery pack at the current moment.

[0103] S180. Determine whether the current maximum slave board temperature is greater than the maximum allowable temperature; if yes, execute S190; if no, execute S160.

[0104] Specifically, if the maximum slave control board temperature at the current moment is greater than the maximum allowable temperature, it indicates that the battery pack balancing is abnormal and the slave control board is at risk of overheating. In this case, balancing is stopped and the main control board is woken up. If the maximum slave control board temperature at the current moment is less than the maximum allowable temperature, it indicates that the battery pack balancing is normal and the slave control board temperature rise is normal. In this case, offline balancing of the battery pack continues.

[0105] S190, Stop balancing and wake up the main control board.

[0106] In addition, anomaly detection during offline battery pack equalization can also be achieved based on the temperature and voltage of the cells within the battery pack. When the temperature of a cell exceeds the maximum cell temperature threshold and / or the cell voltage exceeds the maximum cell voltage threshold, equalization is stopped and the main control board is activated. The maximum cell temperature threshold is a pre-set maximum temperature of a single cell during battery pack equalization; the maximum cell voltage threshold is a pre-set maximum voltage of a single cell during battery pack equalization.

[0107] Example 5

[0108] Figure 5 This is a schematic diagram of an energy storage device provided in Embodiment 5 of the present invention. This embodiment provides an energy storage device. (Refer to...) Figure 5 The energy storage device 100 includes a main control board 110, a battery pack 130, and at least one slave control board 120.

[0109] The slave control board 120 is connected to the battery pack 130; the slave control board 120 is also connected to the main control board 110; the battery pack 130 is used to store electrical energy; the main control board 110 and each slave control board 120 are used to execute the battery pack offline balancing method provided in any of the above embodiments. The main control board 110 and the slave control boards 120 constitute a battery management system, which is capable of performing online and offline balancing of the battery pack.

[0110] The energy storage device 100 provided in this embodiment of the invention has the beneficial effects of the battery pack offline balancing method provided in any of the above embodiments, which will not be repeated here.

[0111] Example 6

[0112] Figure 6This is a schematic diagram of the structure of an electronic device provided in Embodiment Six of the present invention. The electronic device is intended to represent various forms of digital computers, such as laptop computers, desktop computers, workstations, personal digital assistants, servers, blade servers, mainframe computers, and other suitable computers. The electronic device can also represent various forms of mobile devices, such as personal digital processors, cellular phones, smartphones, wearable devices (such as helmets, glasses, watches, etc.), and other similar computing devices. The components shown herein, their connections and relationships, and their functions are merely illustrative and are not intended to limit the implementation of the invention described and / or claimed herein.

[0113] like Figure 6 As shown, the electronic device 10 includes at least one processor 11 and a memory, such as a read-only memory (ROM) 12 or a random access memory (RAM) 13, communicatively connected to the at least one processor 11. The memory stores computer programs executable by the at least one processor. The processor 11 can perform various appropriate actions and processes based on the computer program stored in the ROM 12 or loaded from storage unit 18 into the RAM 13. The RAM 13 may also store various programs and data required for the operation of the electronic device 10. The processor 11, ROM 12, and RAM 13 are interconnected via a bus 14. An input / output (I / O) interface 15 is also connected to the bus 14.

[0114] Multiple components in electronic device 10 are connected to I / O interface 15, including: input unit 16, such as keyboard, mouse, etc.; output unit 17, such as various types of displays, speakers, etc.; storage unit 18, such as disk, optical disk, etc.; and communication unit 19, such as network card, modem, wireless transceiver, etc. Communication unit 19 allows electronic device 10 to exchange information / data with other devices through computer networks such as the Internet and / or various telecommunications networks.

[0115] Processor 11 can be a variety of general-purpose and / or special-purpose processing components with processing and computing capabilities. Some examples of processor 11 include, but are not limited to, a central processing unit (CPU), a graphics processing unit (GPU), various special-purpose artificial intelligence (AI) computing chips, various processors running machine learning model algorithms, a digital signal processor (DSP), and any suitable processor, controller, microcontroller, etc. Processor 11 performs the various methods and processes described above, such as the battery pack offline balancing method.

[0116] In some embodiments, the battery pack offline balancing method may be implemented as a computer program tangibly contained in a computer-readable storage medium, such as storage unit 18. In some embodiments, part or all of the computer program may be loaded and / or installed on electronic device 10 via ROM 12 and / or communication unit 19. When the computer program is loaded into RAM 13 and executed by processor 11, one or more steps of the battery pack offline balancing method described above may be performed. Alternatively, in other embodiments, processor 11 may be configured to perform the battery pack offline balancing method by any other suitable means (e.g., by means of firmware).

[0117] Various embodiments of the systems and techniques described above herein can be implemented in digital electronic circuit systems, integrated circuit systems, field-programmable gate arrays (FPGAs), application-specific integrated circuits (ASICs), application-specific standard products (ASSPs), systems-on-a-chip (SoCs), payload-programmable logic devices (CPLDs), computer hardware, firmware, software, and / or combinations thereof. These various embodiments may include implementations in one or more computer programs that can be executed and / or interpreted on a programmable system including at least one programmable processor, which may be a dedicated or general-purpose programmable processor, capable of receiving data and instructions from a storage system, at least one input device, and at least one output device, and transmitting data and instructions to the storage system, the at least one input device, and the at least one output device.

[0118] Computer programs used to implement the methods of the present invention may be written in any combination of one or more programming languages. These computer programs may be provided to a processor of a general-purpose computer, a special-purpose computer, or other programmable data processing device, such that when executed by the processor, the computer programs cause the functions / operations specified in the flowcharts and / or block diagrams to be performed. The computer programs may be executed entirely on a machine, partially on a machine, or as a standalone software package, partially on a machine and partially on a remote machine, or entirely on a remote machine or server.

[0119] In the context of this invention, a computer-readable storage medium can be a tangible medium that may contain or store a computer program for use by or in conjunction with an instruction execution system, apparatus, or device. A computer-readable storage medium may include, but is not limited to, electronic, magnetic, optical, electromagnetic, infrared, or semiconductor systems, apparatus, or devices, or any suitable combination thereof. Alternatively, a computer-readable storage medium may be a machine-readable signal medium. More specific examples of machine-readable storage media include electrical connections based on one or more wires, portable computer disks, hard disks, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM or flash memory), optical fibers, portable compact disk read-only memory (CD-ROM), optical storage devices, magnetic storage devices, or any suitable combination thereof.

[0120] To provide interaction with a user, the systems and techniques described herein can be implemented on an electronic device having: a display device (e.g., a CRT (cathode ray tube) or LCD (liquid crystal display) monitor) for displaying information to the user; and a keyboard and pointing device (e.g., a mouse or trackball) through which the user provides input to the electronic device. Other types of devices can also be used to provide interaction with the user; for example, feedback provided to the user can be any form of sensory feedback (e.g., visual feedback, auditory feedback, or tactile feedback); and input from the user can be received in any form (including sound input, voice input, or tactile input).

[0121] The systems and technologies described herein can be implemented in computing systems that include backend components (e.g., as data servers), or computing systems that include middleware components (e.g., application servers), or computing systems that include frontend components (e.g., user computers with graphical user interfaces or web browsers through which users can interact with implementations of the systems and technologies described herein), or any combination of such backend, middleware, or frontend components. The components of the system can be interconnected via digital data communication of any form or medium (e.g., communication networks). Examples of communication networks include local area networks (LANs), wide area networks (WANs), blockchain networks, and the Internet.

[0122] A computing system may include clients and servers. Clients and servers are generally geographically separated and typically interact via communication networks. The client-server relationship is established by computer programs running on the respective computers and having a client-server relationship with each other. The server may be a cloud server, also known as a cloud computing server or cloud host, a host product within the cloud computing service system, which addresses the shortcomings of traditional physical hosts and VPS services, such as high management difficulty and weak business scalability. It should be understood that the various forms of processes shown above can be used, with steps reordered, added, or deleted. For example, the steps described in this invention can be executed in parallel, sequentially, or in different orders, as long as the desired result of the technical solution of this invention is achieved; this is not limited herein.

[0123] The specific embodiments described above do not constitute a limitation on the scope of protection of this invention. Those skilled in the art should understand that various modifications, combinations, sub-combinations, and substitutions can be made according to design requirements and other factors. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this invention should be included within the scope of protection of this invention.

Claims

1. A battery pack offline balancing method, characterized in that: The main control board calculates the current balancing duty cycle of the battery pack before the current balancing starts, and sleeps during the offline balancing period of the battery pack; The slave control board balances the battery pack according to the current balancing duty cycle; The battery pack offline balancing method comprises: Obtain the optimal temperature rise rate for this balancing, the number of times the main control board wakes up this time, and the previous balancing duty cycle; wherein the optimal temperature rise rate for this balancing is the average temperature rise rate from the current temperature of the control board to the maximum allowable temperature within the remaining offline balancing time; the previous balancing duty cycle is the balancing duty cycle during the previous balancing; If the number of wake-up times of the main control board is zero, the online temperature rise rate during online balancing is used as the previous balancing temperature rise rate; wherein the online temperature rise rate is the temperature rise rate of the slave control board calculated for the last time before the battery pack is offline balanced; If the number of wake-up times of the main control board is greater than zero, the balanced temperature rise rate during the previous offline balancing is used as the previous balanced temperature rise rate; Calculating the current balanced duty cycle according to the current balanced optimal temperature rise rate, the previous balanced temperature rise rate and the previous balanced duty cycle; The battery pack is balanced according to the current balancing duty cycle.

2. The battery pack offline balancing method according to claim 1, characterized in that: The specific method for obtaining the equilibrium temperature rise rate during the previous offline equilibrium includes: Obtain the slave control board temperature before the last offline balancing, the slave control board temperature after the last offline balancing, and the last offline balancing time; Calculating a temperature difference according to the temperature of the slave control board before the previous offline balancing and the temperature of the slave control board after the previous offline balancing; The equalization temperature rise rate during the previous offline equalization is calculated according to the temperature difference and the previous offline equalization time.

3. The battery pack offline balancing method according to claim 1, characterized in that: The specific method for obtaining the optimal temperature rise rate for this equilibrium includes: Obtain the current maximum slave control board temperature, the maximum allowable temperature and the remaining offline balancing time; wherein the current maximum slave control board temperature is the temperature of the slave control board with the highest temperature at the current moment; Calculate the maximum temperature difference according to the current maximum slave control board temperature and the maximum allowable temperature; The optimal temperature rise rate for this equalization is calculated according to the maximum temperature difference and the remaining offline equalization time.

4. The battery pack offline balancing method according to claim 3, characterized in that: The specific method for obtaining the remaining offline balancing time includes: Obtain the total offline balancing time and the offline balancing elapsed time; wherein the offline balancing elapsed time is the time interval between the offline balancing start time and the current time; The remaining offline balancing time is calculated according to the total offline balancing time and the offline balancing elapsed time.

5. The battery pack offline balancing method according to claim 4, characterized in that: The time interval between each wake-up of the main control board is equal; The specific methods for obtaining offline balancing elapsed time include: Get the wake-up interval of the main control board; The offline balancing elapsed time is calculated according to the number of wake-up times of the main control board this time and the wake-up interval duration.

6. The battery pack offline balancing method according to claim 1, characterized in that: The battery management system includes a main control board and at least one slave control board; Before obtaining the optimal temperature rise rate of this balance, the number of wake-up times of the main control board this time and the previous balance duty cycle, it also includes: Obtain the fault level of the battery management system, battery pack power, maximum slave control board temperature, and single cell power difference; If the fault level of the battery management system is less than the preset level, the battery pack power is greater than the preset power threshold, the maximum slave control board temperature is less than the protection threshold, and the single cell power difference is greater than the opening threshold, then obtain the optimal temperature rise rate for this balancing, the number of wake-up times of the main control board this time, and the previous balancing duty cycle; If the fault level of the battery management system is greater than or equal to the preset level, the battery pack power is less than or equal to the preset power threshold, the maximum slave control board temperature is greater than or equal to the protection threshold, or the single cell power difference is less than or equal to the start threshold, the battery pack is controlled to sleep.

7. The battery pack offline balancing method according to any one of claims 1 to 6, characterized in that: After balancing the battery pack according to the current balancing duty cycle, the method further includes: Get the maximum slave control board temperature at the current moment; If the maximum slave control board temperature at the current moment is greater than the maximum allowable temperature, balancing is stopped and the master control board is awakened.

8. An energy storage device, characterized in that: It includes a main control board, a battery pack and at least one slave control board; The slave control board is connected to the battery pack; the slave control board is also connected to the master control board; The battery pack is used to store electrical energy; the main control board and each of the slave control boards are used to execute the battery pack offline balancing method as described in any one of claims 1-7.

9. An electronic device, characterized in that: The electronic device comprises: at least one processor; and a memory communicatively connected to the at least one processor; wherein, The memory stores a computer program executable by the at least one processor, and the computer program is executed by the at least one processor so that the at least one processor can execute the battery pack offline balancing method according to any one of claims 1 to 7.

10. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores computer instructions, and the computer instructions are used to enable a processor to implement the battery pack offline balancing method according to any one of claims 1 to 7 when executed.

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