Method, device, equipment, storage medium and program product for regulating energy storage device

Abstract

The application relates to an energy storage device adjusting method, device, equipment, storage medium and program product. The method comprises the following steps: in the case that the energy storage device is charged or discharged, the direct charging circuit connected between each battery device and the bus module in the energy storage device is controlled to be turned on, and the current value of each battery device in the energy storage device is obtained; the direct charging circuit is connected with at least one pre-charging circuit in parallel, the resistance value of the pre-charging circuit is greater than that of the direct charging circuit; according to the circulating current threshold value of each battery device and the current value of each battery device, a target battery device is determined from the plurality of battery devices in the energy storage device; and the target pre-charging circuit corresponding to the target battery device is controlled to be turned on and the target direct charging circuit corresponding to the target battery device is controlled to be turned off. The method can improve the stability and reliability of the energy storage device.

Description

Technical Field

[0001] This application relates to the field of new energy technology, and in particular to a method, apparatus, equipment, storage medium and program product for regulating an energy storage device. Background Technology

[0002] With the rapid development of the new energy industry, energy storage devices are being used more and more widely. Energy storage devices are usually constructed by connecting multiple battery devices in parallel, and large-scale energy storage and release are achieved through the coordinated work of the battery devices.

[0003] In related technologies, since at least some of the battery devices connected in parallel in an energy storage device have different voltages, a circulating current phenomenon will occur between the multiple battery devices, which will affect the stability and reliability of the energy storage device operation.

[0004] Therefore, there is an urgent need for a technology that can regulate the circulating current generated between multiple battery devices in an energy storage device to improve the stability and reliability of the energy storage device operation. Summary of the Invention

[0005] Based on this, this application provides a method, apparatus, equipment, storage medium, and program product for regulating an energy storage device, which can improve the stability and reliability of the energy storage device operation.

[0006] In a first aspect, this application provides a method for regulating an energy storage device. The method includes: when the energy storage device is either charging or discharging off, controlling the direct charging circuit connecting each battery device in the energy storage device to a current collector module to be turned on, and acquiring the current value of each battery device in the energy storage device; connecting at least one pre-charging circuit in parallel with the direct charging circuit, wherein the resistance of the pre-charging circuit is greater than the resistance of the direct charging circuit; determining a target battery device from among multiple battery devices in the energy storage device based on the circulating current critical threshold of each battery device and the current value of each battery device; determining the circulating current critical threshold of each battery device based on the charging / discharging state of each battery device and the current state data of each battery device; and controlling the target pre-charging circuit corresponding to the target battery device to be turned on and the corresponding target direct charging circuit to be turned off.

[0007] In the technical solution provided in this application embodiment, a target battery device is determined from multiple battery devices in the energy storage device based on the circulating current critical threshold and the current value of each battery device. The target pre-charge circuit corresponding to the target battery device is turned on and the target direct charge circuit corresponding to the target battery device is turned off, thereby reducing the operating current of the target battery device and avoiding excessive operating current. As a result, this application embodiment has a lower impact on cell life and reduces the probability of overcharging or over-discharging of the target battery device in the energy storage device, thereby reducing the probability of cell failure and the probability of frequent power-off of the battery device. Therefore, it can improve the stability and reliability of the energy storage device operation. In addition, when the energy storage device is turned off for charging or discharging, the direct charge circuit / target pre-charge circuit connected between each battery device and the current collector module in the energy storage device is turned on. The circulating current formed among multiple battery devices in the energy storage device will make the voltage among the battery devices in the energy storage device tend to be balanced, thereby reducing the conduction frequency of the pre-charge circuit when multiple battery devices in the energy storage device are subjected to high voltage, that is, reducing the number of pre-charges, thereby improving the high voltage efficiency of multiple battery devices in the energy storage device.

[0008] In some embodiments, the method further includes: when the current value of the target battery device drops to a circulating current setting threshold, controlling the target direct charging circuit corresponding to the target battery device to be turned on and the target pre-charging circuit corresponding to the target battery device to be turned off.

[0009] In the technical solution provided in this application embodiment, when the battery device switches to the pre-charging circuit due to excessive circulating current, the high resistance of the pre-charging circuit will gradually reduce the current of the battery device. When the current drops to a safe circulating current setting threshold, it switches back to the low resistance direct charging circuit. This can avoid the current from generating additional energy loss in the high resistance circuit for a long time, and can also prevent the problem of severe heat generation of the pre-charging resistor due to prolonged use of the pre-charging circuit, thus extending the service life of the pre-charging resistor.

[0010] In some embodiments, the method further includes: acquiring the charge / discharge state of each battery device and current state data of each battery device; the current state data includes the current temperature and the current state of charge; determining the circulating current allowable threshold corresponding to each battery device based on the charge / discharge state of each battery device and the current state data of each battery device; and determining the circulating current critical threshold of each battery device based on the acquired circulating current cutoff time and the circulating current allowable threshold corresponding to each battery device.

[0011] In the technical solution provided by this application embodiment, the circulating current allowable threshold for each battery device is determined based on the charging / discharging state, current temperature, and current state of charge of each battery device. The circulating current allowable threshold for each battery device is precisely matched with its own real-time state, avoiding the use of a uniform fixed threshold. This avoids situations where some battery devices face safety risks due to excessively high thresholds, thus improving the reliability of battery device operation. Alternatively, it avoids situations where some battery devices frequently trigger the target pre-charge circuit due to excessively low thresholds, leading to increased energy consumption by the resistor and reduced efficiency of voltage balancing among multiple battery devices in the energy storage device. Therefore, this application embodiment can reduce energy loss and improve the efficiency of voltage balancing among multiple battery devices in the energy storage device. Furthermore, by determining the circulating current critical threshold for each battery device based on the obtained circulating current cutoff time and the circulating current allowable threshold corresponding to each battery device, the flexibility of the circulating current critical threshold is improved.

[0012] In some embodiments, determining the circulating current allowable threshold for each battery device based on the charge / discharge state of each battery device and the current state data of each battery device includes: determining the health state data of each battery device based on the acquired historical operating state data of each battery device; determining a circulating current threshold table that matches both the charge / discharge state of each battery device and the health state data of each battery device; the circulating current threshold table includes current values ​​that match each of a plurality of temperatures and each of a plurality of states of charge; and determining the current values ​​in the circulating current threshold table that match the current state data of each battery device as the circulating current allowable threshold for each battery device.

[0013] The technical solution provided in this application combines multiple dimensions such as health status, charge / discharge status, real-time temperature, and state of charge to determine the circulating current allowable threshold. This avoids the problem of unreasonable thresholds caused by using a uniform standard or ignoring individual differences in equipment. It ensures that battery devices in poor health status can receive stricter protection, while allowing battery devices in good status to fully perform. This significantly improves the matching degree between the circulating current allowable threshold and the actual load-bearing capacity of the battery device, thereby improving the operating efficiency of the battery device in the energy storage device while ensuring the safe operation of the energy storage device.

[0014] In some embodiments, the current temperature of each battery device includes the current maximum temperature and the current minimum temperature of the cells in each battery device; the current state of charge of each battery device includes the current maximum state of charge and the current minimum state of charge of the cells in each battery device; determining the current value matching the current state data of each battery device in the circulating current threshold table as the circulating current allowable threshold for each battery device includes: determining a first current value matching the current maximum temperature and the current maximum state of charge, a second current value matching the current maximum temperature and the current minimum state of charge, a third current value matching the current minimum temperature and the current maximum state of charge, and a fourth current value matching the current minimum temperature and the current minimum state of charge from the circulating current threshold table; and determining the minimum current value among the first current value, the second current value, the third current value, and the fourth current value as the circulating current allowable threshold for each battery device.

[0015] In the technical solution provided in this application embodiment, if the temperature of the battery cell in the battery device is too high or too low, or if the state of charge of the battery cell in the battery device is too high or too low, the corresponding current value in the circulating current threshold table will be small. By determining the current value of the battery device under four extreme states, it is equivalent to fully covering the most unfavorable operating conditions that the battery device may face. Then, the minimum current value among the current values ​​under the four extreme states is used as the circulating current allowable threshold of the battery device, thereby ensuring that no matter what state the battery device is in, the circulating current allowable threshold will not exceed the safety limit that the battery cell can withstand under that state. This reduces the risk of battery cell failure due to excessive current in the battery device and improves the stability of the battery device operation.

[0016] In some embodiments, determining the critical threshold of the circulating current for each battery device based on the acquired circulating current cutoff duration and the circulating current allowable threshold corresponding to each battery device includes: acquiring the charge / discharge cutoff duration of the energy storage device when charging or discharging is cut off; when the circulating current cutoff duration is greater than or equal to the charge / discharge cutoff duration, determining the circulating current allowable threshold corresponding to each battery device as the critical threshold of the circulating current for each battery device; when the circulating current cutoff duration is less than the charge / discharge cutoff duration, determining a circulating current adjustment coefficient based on the circulating current cutoff duration and the charge / discharge cutoff duration, and adjusting the circulating current allowable threshold corresponding to each battery device using the circulating current adjustment coefficient to obtain the critical threshold of the circulating current for each battery device.

[0017] In the technical solution provided in this application embodiment, cell voltage balancing in the battery device is a key link to ensure the stable operation of the energy storage device. When the cell voltage in the battery device reaches a balanced state, it can avoid overcharging or over-discharging of individual cells, which would affect the overall performance of the battery device. When the circulating current cutoff time is long, the circulating current allowable threshold is determined as the circulating current critical threshold, so as not to affect the duration of the circulating current. When the circulating current cutoff time is short, the circulating current allowable threshold is adjusted by the circulating current adjustment coefficient, which can reduce the circulating current critical threshold, thereby further reducing the circulating current of the energy storage device and improving the reliability of the battery device operation in the energy storage device.

[0018] In some embodiments, when the energy storage device is shut down for charging or discharging, controlling the direct charging circuit connecting each battery device in the energy storage device to the busbar module to be turned on includes: when the energy storage device is shut down for charging or discharging, acquiring the voltage values ​​of multiple battery devices in the energy storage device; and when the difference between the maximum voltage value and the minimum voltage value among the voltage values ​​of the multiple battery devices is less than a preset voltage threshold, controlling the direct charging circuit connecting each battery device in the energy storage device to the busbar module to be turned on.

[0019] In the technical solution provided in this application embodiment, if the voltage difference between battery devices is too large, forcibly turning on the direct charging circuit may lead to excessive circulating current, causing problems such as heat generation and component loss. However, when the voltage difference is less than the preset voltage threshold, the voltage of each battery device is in a relatively balanced state. At this time, turning on the direct charging circuit can avoid the risk of abnormal circulating current caused by voltage imbalance, effectively prevent the safety hazards caused by turning on the direct charging circuit due to excessive voltage difference of battery devices after the charging and discharging is cut off, and improve the operational reliability of the energy storage device.

[0020] In some embodiments, the method further includes: when the difference between the maximum voltage value and the minimum voltage value is greater than or equal to a preset voltage threshold, determining at least two designated battery devices that need to be balanced based on the maximum voltage value, the minimum voltage value, and characteristic values ​​of the voltages of the plurality of battery devices; and controlling the direct charging circuit of the at least two designated battery devices to be turned on so that the difference between the maximum voltage value and the minimum voltage value is less than the preset voltage threshold.

[0021] In the technical solution provided in this application embodiment, the designated battery devices that need to be balanced are determined based on the maximum voltage value, the minimum voltage value, and the characteristic values ​​of the voltages of multiple battery devices. Only their direct charging circuits are turned on, allowing energy to flow directionally between these designated battery devices. The energy of the high-voltage designated battery device is transferred to the low-voltage designated battery device through the busbar module, thereby reducing the voltage difference between at least two designated battery devices. This creates conditions for the conduction control of the direct charging circuit connecting each battery device and the busbar module in the energy storage device, improving the operational reliability of the energy storage device.

[0022] In some embodiments, the characteristic values ​​of the voltages of the plurality of battery devices include the average voltage value of the voltages of the plurality of battery devices; determining at least two designated battery devices that need to be balanced based on the maximum voltage value, the minimum voltage value, and the characteristic values ​​of the voltages of the plurality of battery devices includes: determining at least two battery devices with the highest voltage values ​​among the plurality of battery devices as at least two designated battery devices when the difference between the maximum voltage value and the average voltage value is greater than the difference between the average voltage value and the minimum voltage value; and determining at least two battery devices with the lowest voltage values ​​among the plurality of battery devices as at least two designated battery devices when the difference between the maximum voltage value and the average voltage value is less than or equal to the difference between the average voltage value and the minimum voltage value.

[0023] In the technical solution provided in this application embodiment, the dominant factor of voltage imbalance between battery devices is determined based on the difference between the maximum voltage value and the average voltage value, and the difference between the average voltage value and the minimum voltage value. Based on the dominant factor of voltage imbalance between battery devices, a specific battery device is determined, which avoids the inability to quickly achieve the goal of the difference between the maximum voltage value and the minimum voltage value being less than the preset voltage threshold due to unclear balancing direction, thereby improving the accuracy of voltage regulation of battery devices in energy storage devices.

[0024] In some embodiments, determining a target battery device from a plurality of battery devices in an energy storage device based on the circulating current critical threshold and the current value of each battery device includes: acquiring the charge / discharge state and current state data of each battery device; the current state data includes the current temperature and the current state of charge; determining the maximum operating current value of each battery device based on the charge / discharge state and the current state data of each battery device; the maximum operating current value of each battery device being greater than the circulating current critical threshold of each battery device; and determining the target battery device from a plurality of battery devices in an energy storage device based on the circulating current critical threshold and the maximum operating current value of each battery device.

[0025] In the technical solution provided in this application embodiment, the target battery device is not only selected from multiple battery devices based on the circulating current critical threshold of each battery device, but also selected from multiple battery devices based on the maximum operating current value of each battery device. This avoids the problem of inaccurate determination of the target battery device that needs current adjustment from multiple battery devices in the energy storage device by using a single threshold, and improves the accuracy of the determined target battery device that needs current adjustment.

[0026] In some embodiments, determining a target battery device from a plurality of battery devices in an energy storage device based on the circulating current critical threshold and the maximum operating current value of each battery device includes: determining at least one candidate battery device from the plurality of battery devices in the energy storage device whose current value is greater than the circulating current critical threshold and less than the maximum operating current value of each battery device, and whose state of charge meets the equalization processing conditions; determining at least one alternative battery device from the plurality of battery devices in the energy storage device whose current value is greater than or equal to the maximum operating current value of each battery device; and merging at least one candidate battery device and at least one alternative battery device to obtain the target battery device.

[0027] In the technical solution provided in this application embodiment, a target battery device is obtained by merging at least one candidate battery device and at least one alternative battery device. Thus, the target battery device covers both battery devices with high current that require state-of-charge balancing and battery devices with current exceeding the maximum operating current. This not only avoids the problem of overcharging or over-discharging of at least one cell in the battery device, but also avoids the problem of cell failure caused by the operating current of the cell in the battery device exceeding the maximum operating current, thereby improving the reliability of the battery device operation in the energy storage device.

[0028] In some embodiments, the equalization processing conditions include at least one of the following: the difference between the maximum and minimum states of charge among the multiple cells in the battery device is greater than or equal to a preset state of charge; the charge / discharge state of the battery device is a charging state, and the difference between the fully charged state and the maximum state of charge among the multiple cells in the battery device is less than or equal to a specified state of charge; the charge / discharge state of the battery device is a discharging state, and the difference between the minimum state of charge and the zero state of charge among the multiple cells in the battery device is less than or equal to a specified state of charge.

[0029] In the technical solution provided in this application embodiment, when the difference between the maximum and minimum state of charge of multiple cells in a battery device is greater than or equal to a preset state of charge, it indicates that the cells in the battery device are prone to overcharging and over-discharging risks. In the charging state, when the difference between the full state of charge and the maximum state of charge among the multiple cells in the battery device is less than or equal to a specified state of charge, it indicates that some cells are close to being fully charged and are prone to overcharging risks. In the discharging state, if the difference between the minimum state of charge and the zero state of charge among the multiple cells in the battery device is less than or equal to a specified state of charge, it indicates that some cells are close to being discharged and are prone to over-discharging risks. This reduces the operating current of the target battery device that is prone to overcharging or over-discharging risks, allowing the target battery device sufficient time to equalize the state of charge of the included cells, thereby improving the risk of overcharging or over-discharging of cells in the energy storage device and improving the operational reliability of the energy storage device.

[0030] In some embodiments, the method further includes: determining the balancing time of the cells in the target battery device based on the obtained state of charge of multiple cells in the target battery device; determining the required resistance value of the pre-charging circuit corresponding to the target battery device based on the balancing time of the cells in the target battery device; and determining a target pre-charging circuit from at least one pre-charging circuit based on the required resistance value of the pre-charging circuit corresponding to the target battery device.

[0031] In the technical solution provided in this application embodiment, the required resistance value of the pre-charging circuit corresponding to the target battery device is determined based on the equalization time of the cells in the target battery device. Then, based on the required resistance value of the pre-charging circuit corresponding to the target battery device, a target pre-charging circuit is determined from at least one pre-charging circuit. The selected target pre-charging circuit can provide appropriate current limiting, which will not lead to a small current in the target battery device due to an excessively large resistance value of the target pre-charging circuit, thus causing low voltage equalization efficiency between battery devices, thereby improving the voltage equalization efficiency between battery devices and reducing energy loss. Conversely, it will not lead to a large current in the target battery device due to an excessively small resistance value of the target pre-charging circuit, thus causing overcharging or over-discharging of the cells in the battery device, thereby improving the operational reliability of the energy storage device.

[0032] Secondly, this application provides an adjustment device for an energy storage device, comprising: a control module for controlling the direct charging circuit connecting each battery device in the energy storage device to the current collector module to be turned on when the energy storage device is turned off during charging or discharging; at least one pre-charging circuit is connected in parallel to the direct charging circuit, the resistance of the pre-charging circuit being greater than the resistance of the direct charging circuit; an acquisition module for acquiring the current value of each battery device in the energy storage device; a determination module for determining a target battery device from multiple battery devices in the energy storage device based on the circulating current critical threshold of each battery device and the current value of each battery device; the circulating current critical threshold of each battery device is determined based on the charging and discharging state of each battery device and the current state data of each battery device; the control module is further configured to control the target pre-charging circuit corresponding to the target battery device to be turned on and the target direct charging circuit corresponding to the target battery device to be turned off.

[0033] Thirdly, this application provides a control device, including a memory and a processor, wherein the memory stores a computer program, and the processor executes the computer program to implement the steps of the method of any one of the first aspects.

[0034] Fourthly, this application provides a computer-readable storage medium having a computer program stored thereon, wherein the computer program, when executed by a processor, implements the steps of the method of any one of the first aspects.

[0035] Fifthly, this application provides a computer program product, including a computer program, wherein when the computer program is executed by a processor, it implements the steps of the method of any one of the first aspects. Attached Figure Description

[0036] To more clearly illustrate the technical solutions in the embodiments of this application or related technologies, the drawings used in the description of the embodiments of this application or related technologies will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0037] Figure 1 This is a structural schematic diagram of an energy storage container for some embodiment systems;

[0038] Figure 2 A circuit diagram of an energy storage device provided for some embodiments;

[0039] Figure 3 Circuit diagrams of energy storage devices provided for other embodiments;

[0040] Figure 4 A schematic flowchart illustrating the adjustment method of an energy storage device provided in some embodiments;

[0041] Figure 5 A flowchart illustrating a method for determining the critical threshold of circulation provided in some embodiments;

[0042] Figure 6 A flowchart illustrating a method for determining a target battery device provided in some embodiments;

[0043] Figure 7 A flowchart illustrating a method for determining a target pre-charging circuit as provided in some embodiments;

[0044] Figure 8 A schematic diagram of the regulating device of an energy storage device provided in some embodiments;

[0045] Figure 9 A schematic diagram of the structure of a control device provided for some embodiments. Detailed Implementation

[0046] The embodiments of the technical solution of this application will now be described in detail with reference to the accompanying drawings. These embodiments are only used to more clearly illustrate the technical solution of this application and are therefore merely examples, and should not be used to limit the scope of protection of this application.

[0047] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains; the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the application; the terms “comprising” and “having”, and any variations thereof, in the specification, claims, and foregoing description of the drawings are intended to cover non-exclusive inclusion.

[0048] In the description of the embodiments of this application, technical terms such as "first" and "second" are used only to distinguish different objects and should not be construed as indicating or implying relative importance or implicitly specifying the number, specific order, or primary and secondary relationship of the indicated technical features. In the description of the embodiments of this application, "multiple" means two or more, and "multiple groups" means two or more, unless otherwise explicitly defined. In the description of the embodiments of this application, "each" means each of the multiple options, unless otherwise explicitly defined.

[0049] In this document, the term "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0050] In the description of the embodiments in this application, the term "and / or" is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, and B existing alone. Additionally, the character " / " in this document generally indicates that the preceding and following related objects have an "or" relationship.

[0051] Currently, judging from market trends, energy storage devices are being used more and more widely, bringing great convenience to daily production and life. Energy storage devices include multiple battery units, which can be connected in series, parallel, or a combination of series and parallel connections. For example, in the embodiments of this application, multiple battery units are connected in parallel. Each battery unit in the energy storage device can be charged and discharged. By controlling the charging and discharging of each battery unit, large-scale energy storage and release can be achieved. The battery unit is a whole formed by connecting multiple battery packs together. Exemplarily, a battery unit can be obtained by connecting multiple battery packs in series, parallel, or a combination of series and parallel connections.

[0052] The battery device in this application embodiment may include a battery cluster or a battery cabinet. For example, a battery device includes multiple battery packs connected in series, each battery pack including multiple battery cells connected in series, parallel, or mixed series.

[0053] Energy storage devices may include energy storage containers, energy storage power sources, or other devices capable of storing energy. For example, Figure 1 Here are some schematic diagrams of the energy storage container structure of the embodiment system, such as Figure 1 As shown, an energy storage container can be, for example, a regular cuboid structure, where the six faces of the cuboid serve as the six outer walls of the energy storage device. Setting the energy storage device in a cuboid structure facilitates its fixed placement and transportation. Of course, the energy storage device can also have other shapes; for example, at least one wall of the energy storage device may be angled.

[0054] Figure 2 A circuit structure diagram of an energy storage device provided for some embodiments, such as Figure 2 The energy storage device includes a combiner module and S groups of energy storage modules. Each group of energy storage modules includes a battery unit and a high-voltage box. The high-voltage box includes a pre-charge unit, a positive switch, a negative switch, and a controller. The positive terminal of each battery unit is connected to the combiner module through a pre-charge unit, and the negative terminal of each battery unit is connected to the combiner module through a negative switch, forming a pre-charge circuit (i.e., a circuit where the positive terminal of the battery unit passes through the pre-charge unit, the combiner module, and the negative switch in sequence back to the negative terminal of the battery unit). The positive terminal of each battery unit is also connected to the combiner module through a positive switch, and the negative terminal of each battery unit is connected to the combiner module through a negative switch, forming a high-voltage circuit (i.e., a circuit where the positive terminal of the battery unit passes through the positive switch, the combiner module, and the negative switch in sequence back to the negative terminal of the battery unit). The control terminals of the pre-charge unit, the positive switch, and the negative switch in each group of energy storage modules are all connected to the controller in that group of energy storage modules, so that the controller can control the conduction, disconnection, conduction, and disconnection of the pre-charge circuit, the high-voltage circuit, and the high-voltage circuit in that group of energy storage modules.

[0055] The switches in the embodiments of this application may include relays / circuit breakers, disconnect switches, or metal-oxide-semiconductor field-effect transistor (MOSFET or MOS) switches.

[0056] It should be noted that, Figure 2 This is merely a schematic diagram of the circuit structure of an energy storage device. In other embodiments, the energy storage device may have other circuit structures, for example... Figure 3The circuit structure diagram of the energy storage device provided for other embodiments is shown. The energy storage device includes a combiner module and R groups of energy storage modules. Each group of energy storage modules includes a high-voltage box and multiple battery devices. The high-voltage box includes a controller ( Figure 3 The system comprises a pre-charge unit (not shown), a positive switch, and a negative switch. The control terminals of the pre-charge unit and the switches are both connected to a controller. The positive terminals of multiple battery devices in each energy storage module are connected to the combiner module via the pre-charge unit. The negative terminals of each battery device in each energy storage module are connected to the combiner module via a negative switch, forming a pre-charge circuit for each battery device. The positive terminals of each battery device in each energy storage module are connected to the combiner module via a positive switch, and the negative terminals of each battery device in each energy storage module are connected to the combiner module via a negative switch, forming a high-voltage circuit for each battery device. Multiple battery devices in one energy storage module can share a single controller and a single pre-charge unit. In other embodiments, the positive terminals of multiple battery devices in each energy storage module are connected to the combiner module via a single positive switch.

[0057] When an energy storage device does not need to supply power to external devices (no need for discharging) or does not need to supply power to the energy storage device from external devices (no need for charging), the control equipment in the energy storage device disconnects each of the multiple battery units in the device from the combiner module. This allows the multiple battery units in the energy storage device that have already been charged to high voltage to de-charge. Once the de-charging of all battery units in the energy storage device is complete, the charging or discharging of the energy storage device is cut off. For example, if the energy storage device is supplying power to external devices while multiple battery units are charged to high voltage, the discharging of the energy storage device will be cut off once the de-charging of all battery units is complete. Similarly, if an external device is supplying power to the energy storage device while multiple battery units are charged to high voltage, the charging of the energy storage device will be cut off once the de-charging of all battery units is complete.

[0058] In related technologies, when the energy storage device is shut down for charging or discharging, the battery devices in the energy storage device are not managed. Instead, they wait for the next operating command of the energy storage device. For example, when the energy storage device needs to supply power to external devices, or when external devices need to supply power to the energy storage device, the high voltage is controlled to be applied to multiple battery devices in the energy storage device.

[0059] However, since multiple battery cells in an energy storage device are connected in parallel, taking the discharge of the energy storage device as an example, each battery cell outputs a current to the combiner module, which then aggregates the multiple currents output by the battery cells before outputting the current. Therefore, voltage balancing of the multiple battery cells is crucial. Related technologies only balance the voltage of the multiple battery cells during the charging or discharging process of the energy storage device. However, these technologies often use balancing circuits (such as DC-DC circuits) to balance the voltage between the multiple battery cells. These DC-DC circuits create circulating currents among the multiple battery cells in the energy storage device. If the circulating currents among the multiple battery cells are large, it may not only lead to excessive current flowing through the cells in the energy storage device, reducing cell lifespan, but also, due to inconsistencies in the operating states (at least one of voltage, state of charge (SOC), and temperature) of the multiple cells in a single battery cell, it may cause some cells to be overcharged or over-discharged, and may even lead to cell failures and frequent power-offs of the battery device. Therefore, the circulating currents among the multiple battery cells in an energy storage device affect the stability and reliability of the energy storage device's operation. Furthermore, the relevant technologies do not take into account the large voltage differences between multiple battery devices in the energy storage device, which leads to the need for frequent pre-charging during the high-voltage process, resulting in a long high-voltage time for multiple battery devices in the energy storage device and reducing the high-voltage efficiency of multiple battery devices in the energy storage device.

[0060] To alleviate the above problems, research has found that if the voltage of multiple battery devices in the energy storage device is balanced and the circulating current among the multiple battery devices is adjusted when the charging or discharging of the energy storage device is cut off, the operating current of one or more battery devices can be prevented from being too high. This can improve the stability and reliability of the energy storage device and also improve the high voltage efficiency of the multiple battery devices in the energy storage device.

[0061] Based on the above considerations, this application provides an adjustment method for an energy storage device. The method includes: when the energy storage device is shut down for charging or discharging, controlling the direct charging circuit connecting each battery device in the energy storage device to the current combiner module to be turned on, and obtaining the current value of each battery device in the energy storage device; at least one pre-charging circuit is connected in parallel with the direct charging circuit, the resistance of the pre-charging circuit being greater than the resistance of the direct charging circuit; determining a target battery device from multiple battery devices in the energy storage device according to the circulating current critical threshold of each battery device and the current value of each battery device; the circulating current critical threshold of each battery device is determined according to the charging and discharging state of each battery device and the current state data of each battery device; controlling the target pre-charging circuit corresponding to the target battery device to be turned on and the corresponding target direct charging circuit to be turned off.

[0062] In this way, based on the circulating current critical threshold and current value of each battery device, a target battery device is determined from multiple battery devices in the energy storage device. The target pre-charge circuit corresponding to the target battery device is turned on and the target direct charge circuit is turned off, thereby reducing the operating current of the target battery device and avoiding excessive operating current. As a result, the impact on cell life is low in this embodiment, and the probability of overcharging or over-discharging of the target battery device in the energy storage device is reduced, thereby reducing the probability of cell failure and the probability of frequent power-off of the battery device. Therefore, the stability and reliability of the energy storage device are improved. In addition, when the energy storage device is turned off during charging or discharging, the direct charge circuit / target pre-charge circuit connecting each battery device and the current collector module is turned on. The circulating current formed among multiple battery devices in the energy storage device will make the voltage among the battery devices in the energy storage device tend to be balanced, thereby reducing the frequency of pre-charge circuit conduction when multiple battery devices in the energy storage device are under high voltage, i.e., reducing the number of pre-charges, thereby improving the high voltage efficiency of multiple battery devices in the energy storage device.

[0063] Figure 4 A flowchart illustrating a method for regulating an energy storage device according to some embodiments, the method being applied to a control device in the energy storage device, the method comprising:

[0064] S401. When the energy storage device is shut down for charging or discharging, control the direct charging circuit connecting each battery device in the energy storage device to the current combiner module to be turned on, and obtain the current value of each battery device in the energy storage device; the direct charging circuit is connected in parallel with at least one pre-charging circuit, and the resistance of the pre-charging circuit is greater than the resistance of the direct charging circuit.

[0065] The energy storage device in this application embodiment may include any of the energy storage devices listed above.

[0066] When multiple battery cells in an energy storage device complete the high-voltage conversion and the energy storage device disconnects from external devices, the energy storage device either stops charging or discharging. For example, if an external device supplies power to the energy storage device before the high-voltage conversion is completed, this corresponds to the energy storage device stopping charging. Similarly, if the energy storage device supplies power to an external device before the high-voltage conversion is completed, this corresponds to the energy storage device stopping discharging.

[0067] In some embodiments, the direct charging circuit may include circuits containing a positive switch and a negative switch. For example, the positive terminal of each battery device is connected to the combiner module through a corresponding positive switch, and the negative terminal of each battery device is connected to the combiner module through a corresponding negative switch. Exemplarily, there may be a one-to-one correspondence between battery devices and positive switches, or multiple battery devices may correspond to one positive switch, meaning multiple battery devices are all connected to the same positive switch. Exemplarily, there may be a one-to-one correspondence between battery devices and negative switches. Each battery device corresponds to one direct charging circuit, and each battery device is connected to the combiner module through a direct charging circuit to form a high-voltage circuit for each battery device. Controlling the conduction of the direct charging circuit connecting each battery device and the combiner module in the energy storage device may include controlling both the positive and negative switches connecting each battery device and the combiner module in the energy storage device to be turned on.

[0068] In some embodiments, the busbar module includes a busbar component and a bus. The busbar component connects the multiple energy storage modules and is also connected to the busbar to enable power transfer between each battery device and the busbar. For example, the busbar component may include a busbar.

[0069] In some embodiments, a pre-charge circuit may include a series circuit of a pre-charge resistor and a pre-charge switch (i.e., a pre-charge switch sub-circuit) and a circuit containing a negative switch (a negative switch sub-circuit). At least one pre-charge circuit includes at least one pre-charge switch sub-circuit and one negative switch sub-circuit. When there are multiple pre-charge switch sub-circuits, the multiple pre-charge switch sub-circuits are connected in parallel. The positive terminal of each battery device or each plurality of battery devices is connected to the first terminal of at least one pre-charge switch sub-circuit, the second terminal of at least one pre-charge switch sub-circuit is connected to a busbar module, and the negative terminal of each battery device is connected to the busbar module through a negative switch sub-circuit.

[0070] In this embodiment, each battery device in the energy storage device can be connected to the combiner module not only via a direct charging circuit, but also via at least one pre-charging circuit connected in parallel with the direct charging circuit. The control device can control the direct charging circuit connected to each battery device to be turned on and / or off, and can control each pre-charging circuit connected to each battery device to be turned on and / or off.

[0071] In some embodiments, the energy storage device may further include multiple controllers, with each battery device or multiple battery devices in the energy storage device corresponding to one controller. Each controller can acquire the current value of at least one corresponding battery device and send the acquired current value of at least one battery device to a control device. For example, a first terminal of a current detector can be connected to the positive terminal of each battery device in the energy storage device. The second terminal of the current detector is connected not only to the direct charging circuit but also to at least one pre-charging circuit. The output terminal of the current detector is connected to the corresponding controller, so that the controller can acquire the current value of the corresponding at least one battery device.

[0072] In this embodiment, the current value can be positive. At the same time as obtaining the current value, the current direction can also be obtained to determine whether the battery device is in a discharging state or a charging state.

[0073] In the embodiments of this application, the current value of the battery device can be the current value passing through the battery device, for example, the current value output by the battery device, or the current value flowing into the battery device.

[0074] S402. Based on the circulating current critical threshold and the current value of each battery device, determine the target battery device from among the multiple battery devices in the energy storage device.

[0075] The circulating current critical threshold for each battery device is determined based on the charge / discharge state and current state data of each battery device. For example, the current state data includes the current temperature and the current state of charge.

[0076] For example, the target battery device can be one or more. For instance, from the battery devices in the energy storage device, a candidate battery device whose current value exceeds the circulating current critical threshold of each battery device can be identified; and the target battery device can be identified from the candidate battery devices.

[0077] For example, a battery device to be determined can be identified as a target battery device. For instance, if each battery device in the energy storage device corresponds to a circulating current critical threshold, then for any given battery device, if the current value of that battery device exceeds the circulating current critical threshold, that battery device is identified as a target battery device.

[0078] For example, a target battery device can be determined from the pool of battery devices based on the current state data of the cells in the pool of battery devices to be determined. For example, the current state data may include at least one of the following: health status, temperature, state of charge, etc. For example, a battery device that meets at least one of the following conditions can be determined as the target battery device from the pool of battery devices to be determined: at least one cell in the battery device has a health status below a health status threshold; at least one cell in the battery device has a temperature above a preset temperature threshold; at least one cell in the battery device has a state of charge above a high state of charge threshold; at least one cell in the battery device has a state of charge below a low state of charge threshold.

[0079] For example, battery devices whose state of charge (SOC) meets the balancing conditions can be identified as target battery devices. For instance, meeting the balancing conditions means that the SOC value meets the requirement to activate the balancing mechanism to balance the SOC of each battery.

[0080] In some embodiments, each battery device in the energy storage device corresponds to a circulating current critical threshold, meaning that the circulating current critical thresholds of different battery devices may be the same or different.

[0081] S403, Control the target pre-charging circuit corresponding to the target battery device to be turned on and the target direct charging circuit corresponding to be turned off.

[0082] The target pre-charging circuit corresponding to the target battery device can be one or more pre-charging circuits connected to the target battery device. The target pre-charging circuit can be determined based on the required resistance value of the pre-charging circuit corresponding to the target battery device. The resistance value of the target pre-charging circuit can be greater than or equal to the required resistance value of the pre-charging circuit. For example, the required resistance value of the pre-charging circuit can be determined based on the voltage and internal resistance of multiple battery devices in the energy storage device, and / or, the required resistance value of the pre-charging circuit can be determined based on the difference between the current value of the target battery device and the circulating current critical threshold of the target battery device.

[0083] By controlling the target pre-charge circuit corresponding to the target battery device to be turned on and the target direct charge circuit corresponding to it to be turned off, the resistance in the circuit connecting the target battery device to other battery devices is increased, thereby reducing the current passing through the target battery device. The higher the resistance of the target pre-charge circuit, the greater the decrease in the current of the target battery device.

[0084] Specifically, when the target pre-charging circuit corresponding to the target battery device is turned on and the target direct charging circuit is turned off, the current value of the target battery device is less than or equal to the corresponding circulating current critical threshold due to the effect that the resistance value of the pre-charging circuit is greater than the resistance value of the direct charging circuit. Furthermore, through the circulating current effect among multiple battery devices in the energy storage device, the voltage difference among multiple battery devices in the energy storage device gradually decreases, thereby gradually reducing the current value of the target battery device.

[0085] In some embodiments, after S403, the following steps may be included: obtaining a high-voltage command for the battery devices in the energy storage device, controlling the direct charging circuit connected between each battery device in the energy storage device and the combiner module to disconnect, and controlling the pre-charging circuit connected between each battery device in the energy storage device and the combiner module to disconnect, and controlling the multiple battery devices in the energy storage device to sequentially apply high voltage according to the current voltage of the multiple battery devices in the energy storage device.

[0086] In the technical solution provided in this application embodiment, a target battery device is determined from multiple battery devices in the energy storage device based on the circulating current critical threshold and the current value of each battery device. The target pre-charge circuit corresponding to the target battery device is turned on and the target direct charge circuit corresponding to the target battery device is turned off, thereby reducing the operating current of the target battery device and avoiding excessive operating current. As a result, this application embodiment has a lower impact on cell life and reduces the probability of overcharging or over-discharging of the target battery device in the energy storage device, thereby reducing the probability of cell failure and the probability of frequent power-off of the battery device. Therefore, it can improve the stability and reliability of the energy storage device operation. In addition, when the energy storage device is turned off for charging or discharging, the direct charge circuit / target pre-charge circuit connected between each battery device and the current collector module in the energy storage device is turned on. The circulating current formed among multiple battery devices in the energy storage device will make the voltage among the battery devices in the energy storage device tend to be balanced, thereby reducing the conduction frequency of the pre-charge circuit when multiple battery devices in the energy storage device are subjected to high voltage, that is, reducing the number of pre-charges, thereby improving the high voltage efficiency of multiple battery devices in the energy storage device.

[0087] In some embodiments, after S403, the following steps may be included: when the current value of the target battery device drops to the circulating current setting threshold, controlling the target direct charging circuit corresponding to the target battery device to be turned on and the target pre-charging circuit corresponding to be turned off.

[0088] The circulating current setting threshold is lower than the circulating current critical threshold. For example, the circulating current setting threshold is lower than the circulating current critical threshold of each battery device. In some embodiments, the circulating current setting threshold may be a pre-configured threshold. In other embodiments, the circulating current setting threshold may be a threshold determined based on the state data of the battery device. In some embodiments, all battery devices in the energy storage device correspond to the same circulating current setting threshold, and the circulating current setting thresholds corresponding to different battery devices may be the same; alternatively, each battery device in the energy storage device corresponds to a circulating current setting threshold, and the circulating current setting thresholds corresponding to different battery devices may be the same or different.

[0089] In some embodiments, the circulating current setting threshold can be 0, or the circulating current setting threshold is greater than 0, and the difference between it and 0 is less than or equal to a preset current value. For example, the circulating current setting threshold can be close to 0, for example, the circulating current setting threshold can be 0.01 to 1 ampere (A). For example, the circulating current setting threshold can be 0.01A, 0.1A, or 1A.

[0090] In some embodiments, the circulating current setting threshold can be determined as follows: Before controlling the target pre-charge circuit corresponding to the target battery device to be turned on and the corresponding target direct charge circuit to be turned off, the current difference between the current value of the target battery device before the corresponding target pre-charge circuit is turned on and the circulating current critical threshold of the target battery device is obtained, and this current difference is used as the current offset value. When controlling the target pre-charge circuit corresponding to the target battery device to be turned on and the corresponding target direct charge circuit to be turned off, the adjusted current value of the target battery device is obtained, and the current difference between the adjusted current value of the target battery device and the current offset value is used as the setting current value. If the setting current value is greater than 0, the setting current value is determined as the circulating current setting threshold. If the setting current value is less than 0, 0 is determined as the circulating current setting threshold.

[0091] In the technical solution provided in this application embodiment, when the battery device switches to the pre-charging circuit due to excessive circulating current, the high resistance of the pre-charging circuit will gradually reduce the current of the battery device. When the current drops to a safe circulating current setting threshold, it switches back to the low resistance direct charging circuit. This can avoid the current from generating additional energy loss in the high resistance circuit for a long time, and can also prevent the problem of severe heat generation of the pre-charging resistor due to prolonged use of the pre-charging circuit, thus extending the service life of the pre-charging resistor.

[0092] Figure 5 A flowchart illustrating a method for determining a circulating current critical threshold provided in some embodiments. This method is applied to a control device in an energy storage device and can be executed while controlling the conduction of the direct charging circuit connecting each battery device and the combiner module in the energy storage device. The method includes:

[0093] S501. Obtain the charging and discharging status of each battery device and the current status data of each battery device; the current status data includes the current temperature and the current state of charge.

[0094] Because the voltages of the multiple battery devices in the energy storage device differ, when the direct charging circuit connecting each battery device to the current collector is open, any two battery devices can be directly connected through the current collector, resulting in a circulating current between the battery devices. This causes some battery devices in the energy storage device to be in a charging state while others are in a discharging state, until the voltages of the multiple battery devices reach equilibrium.

[0095] The state of charge / discharge of each battery device may include either a charging state or a discharging state. The current temperature of each battery device includes the current maximum temperature and / or current minimum temperature of the cells within that battery device. The current state of charge of each battery device includes the current maximum state of charge and / or current minimum state of charge of the cells within that battery device.

[0096] The charge / discharge status and current status data of each battery device can be sent from the controller in the energy storage device to the control equipment.

[0097] S502. Based on the charging and discharging status of each battery device and the current status data of each battery device, determine the circulating current allowable threshold corresponding to each battery device.

[0098] For example, the controller may internally store a charging circulating current threshold table that matches the charging state and a discharging circulating current threshold table that matches the discharging state.

[0099] In some embodiments, S502 may include the following steps: for any battery device in a charging state, the control device may obtain a charging circulating current threshold table matching the charging state from internal storage, the charging circulating current threshold table including current values ​​matching each of a plurality of temperatures and each of a plurality of states of charge; and determine the current value in the charging circulating current threshold table that matches the current state data of the battery device in the charging state as the circulating current allowable threshold corresponding to the battery device in the charging state.

[0100] In some embodiments, S502 may include the following steps: for any battery device in a discharge state, the control device may obtain a discharge circulating current threshold table matching the discharge state from internal storage, the discharge circulating current threshold table including current values ​​matching each of a plurality of temperatures and each of a plurality of states of charge; and determine the current value in the discharge circulating current threshold table that matches the current state data of the battery device in the discharge state as the circulating current allowable threshold corresponding to the battery device in the discharge state.

[0101] For example, Table 1 is a schematic diagram of a charging circulating current threshold table that matches the charging state provided in some embodiments, and Table 2 is a schematic diagram of a discharging circulating current threshold table that matches the discharging state provided in some embodiments.

[0102] Table 1

[0103]

[0104] Table 2

[0105]

[0106] For example, a11 / b11 represents the circulating current allowable threshold when the battery's state of charge is 0% and the temperature is less than or equal to -10°C, a12 / b12 represents the circulating current allowable threshold when the battery's state of charge is (0%, 10%) and the temperature is less than or equal to -10°C, a21 / b21 represents the circulating current allowable threshold when the battery's state of charge is 0% and the temperature is (-10°C, 0°C), and so on. Through Tables 1 and 2, the circulating current allowable threshold corresponding to each battery device can be obtained.

[0107] S503. Based on the obtained circulating current cutoff time and the circulating current allowable threshold corresponding to each battery device, determine the circulating current critical threshold of each battery device.

[0108] For example, the circulating current cutoff time can include the duration between the start and end times of the circulating current generated by the battery devices in the energy storage device. For instance, the circulating current start time can be the moment when the direct charging circuit connecting each battery device in the energy storage device to the combiner module is turned on when charging or discharging of the energy storage device is cut off. For instance, the circulating current end time can include when the current value of each battery in the energy storage device is less than or equal to a specified current value. For example, the specified current value can be greater than or equal to 0 amperes and less than or equal to a current value close to 0 amperes.

[0109] For example, the circulating current cutoff time can be determined based on the maximum and minimum voltage values ​​among the voltage values ​​of the multiple battery devices in the energy storage device.

[0110] In some embodiments, S503 may include the following steps: when the circulating current cutoff time is greater than or equal to a preset time, the difference between the circulating current allowable threshold and the preset offset value corresponding to each battery device is determined as the circulating current critical threshold of each battery device; when the circulating current cutoff time is less than the preset time, the circulating current allowable threshold corresponding to each battery device is determined as the circulating current critical threshold of each battery device.

[0111] In some embodiments, S503 may include the following steps: when the circulating current cutoff time is less than a specified time, the sum of the circulating current allowable threshold and the preset offset value corresponding to each battery device is determined as the circulating current critical threshold of each battery device; when the circulating current cutoff time is less than the preset time and greater than or equal to the specified time, the circulating current allowable threshold corresponding to each battery device is determined as the circulating current critical threshold of each battery device.

[0112] In the technical solution provided by this application embodiment, the circulating current allowable threshold for each battery device is determined based on the charging / discharging state, current temperature, and current state of charge of each battery device. The circulating current allowable threshold for each battery device is precisely matched with its own real-time state, avoiding the use of a uniform fixed threshold. This avoids situations where some battery devices face safety risks due to excessively high thresholds, thus improving the reliability of battery device operation. Alternatively, it avoids situations where some battery devices frequently trigger the target pre-charge circuit due to excessively low thresholds, leading to increased energy consumption by the resistor and reduced efficiency of voltage balancing among multiple battery devices in the energy storage device. Therefore, this application embodiment can reduce energy loss and improve the efficiency of voltage balancing among multiple battery devices in the energy storage device. Furthermore, by determining the circulating current critical threshold for each battery device based on the obtained circulating current cutoff time and the circulating current allowable threshold corresponding to each battery device, the flexibility of the circulating current critical threshold is improved.

[0113] In some embodiments, determining the circulating current allowable threshold for each battery device based on the charge / discharge state of each battery device and the current state data of each battery device includes: determining the health state data of each battery device based on the acquired historical operating state data of each battery device; determining a circulating current threshold table that matches both the charge / discharge state of each battery device and the health state data of each battery device; the circulating current threshold table includes current values ​​that match each of a plurality of temperatures and each of a plurality of states of charge; and determining the current values ​​in the circulating current threshold table that match the current state data of each battery device as the circulating current allowable threshold for each battery device.

[0114] In some embodiments, the health status data for each battery device can be the minimum value of the health status data of the multiple cells included in each battery device.

[0115] The circulating current threshold table can be used to determine the current value that matches the current state data of each battery device and is determined as the circulating current allowable threshold for each battery device. The circulating current threshold table includes the current value that matches each of the multiple temperatures and each of the multiple states of charge.

[0116] In some embodiments, the health status data of each cell in each battery device can be determined based on the historical operating status data of each cell in each battery device; and the minimum value of the health status data of the multiple cells included in each battery device can be determined as the health status data of each battery device.

[0117] The historical operating data of the battery device records its performance changes over long-term use. The health status data determined by this data can accurately reflect the current health status of the battery device. For example, a battery device in better health has a stronger ability to withstand circulating current and can be set with a higher circulating current allowable threshold, while a battery device in poor health can be set with a lower circulating current allowable threshold.

[0118] For example, historical operating data may include historical states of charge (SOCs) and corresponding voltage values. The cell's health status data is determined based on the voltage values ​​at full charge in the cell's historical SOCs. For instance, the ratio of the voltage value at full charge closest to the current moment in the cell's historical operating data to the voltage value at full charge during the cell's initial operation can be used to determine the cell's health status data. As another example, the ratio of the voltage value at the target SOC closest to the current moment in the cell's historical operating data to the voltage value at the target SOC during the cell's initial operation can be used to determine the cell's health status data. The target SOC is greater than 0% SOC and less than 100% SOC.

[0119] In some embodiments, the control device may store an ammeter containing multiple health status data of the energy storage device in a charging state and an ammeter containing multiple health status data of the energy storage device in a discharging state; and determine a circulating current threshold table from the stored ammeters that matches both the charging / discharging state of each battery device and the health status data of each battery device.

[0120] For example, the matching health status data can be determined by identifying the health status data that is closest to the health status data of the battery device among multiple health status data that are lower than the health status data of the battery device.

[0121] The technical solution provided in this application combines multiple dimensions such as health status, charge / discharge status, real-time temperature, and state of charge to determine the circulating current allowable threshold. This avoids the problem of unreasonable thresholds caused by using a uniform standard or ignoring individual differences in equipment. It ensures that battery devices in poor health status can receive stricter protection, while allowing battery devices in good status to fully perform. This significantly improves the matching degree between the circulating current allowable threshold and the actual load-bearing capacity of the battery device, thereby improving the operating efficiency of the battery device in the energy storage device while ensuring the safe operation of the energy storage device.

[0122] In some embodiments, the current temperature of each battery device includes the current maximum temperature and the current minimum temperature of the cells in each battery device; the current state of charge of each battery device includes the current maximum state of charge and the current minimum state of charge of the cells in each battery device.

[0123] A battery device includes multiple battery cells. The current temperature of the battery device is the current maximum temperature and the current minimum temperature among the current temperatures of the multiple battery cells included in the battery device. The current state of charge of the battery device is the current maximum state of charge and the current minimum state of charge among the current states of charge of the multiple battery cells included in the battery device.

[0124] For example, the current temperature and current state of charge of multiple cells in each battery device can be transmitted from each controller in the energy storage device to the control device. The control device determines the current maximum temperature and current minimum temperature of the cells in each battery device, as well as the current maximum state of charge and current minimum state of charge of the cells in each battery device, based on the current temperature and current state of charge of the multiple cells in each battery device.

[0125] In some embodiments, determining the current value matching the current state data of each battery device in the circulating current threshold table as the circulating current allowable threshold for each battery device includes: determining a first current value matching the current maximum temperature and the current maximum state of charge, a second current value matching the current maximum temperature and the current minimum state of charge, a third current value matching the current minimum temperature and the current maximum state of charge, and a fourth current value matching the current minimum temperature and the current minimum state of charge from the circulating current threshold table; and determining the minimum current value among the first current value, the second current value, the third current value, and the fourth current value as the circulating current allowable threshold for each battery device.

[0126] In the technical solution provided in this application embodiment, if the temperature of the battery cell in the battery device is too high or too low, or if the state of charge of the battery cell in the battery device is too high or too low, the corresponding current value in the circulating current threshold table will be small. By determining the current value of the battery device under four extreme states, it is equivalent to fully covering the most unfavorable operating conditions that the battery device may face. Then, the minimum current value among the current values ​​under the four extreme states is used as the circulating current allowable threshold of the battery device, thereby ensuring that no matter what state the battery device is in, the circulating current allowable threshold will not exceed the safety limit that the battery cell can withstand under that state. This reduces the risk of battery cell failure due to excessive current in the battery device and improves the stability of the battery device operation.

[0127] In some embodiments, determining the critical threshold of the circulating current for each battery device based on the acquired circulating current cutoff duration and the circulating current allowable threshold corresponding to each battery device includes: acquiring the charge / discharge cutoff duration of the energy storage device when charging or discharging is cut off; when the circulating current cutoff duration is greater than or equal to the charge / discharge cutoff duration, determining the circulating current allowable threshold corresponding to each battery device as the critical threshold of the circulating current for each battery device; when the circulating current cutoff duration is less than the charge / discharge cutoff duration, determining a circulating current adjustment coefficient based on the circulating current cutoff duration and the charge / discharge cutoff duration, and adjusting the circulating current allowable threshold corresponding to each battery device using the circulating current adjustment coefficient to obtain the critical threshold of the circulating current for each battery device.

[0128] In some implementations, determining the circulating current adjustment coefficient based on the circulating current cutoff duration and the charge / discharge cutoff duration may include: determining the circulating current adjustment coefficient based on the ratio of the circulating current cutoff duration to the charge / discharge cutoff duration.

[0129] In some implementations, the critical threshold for the circulating current of each battery device can be determined by multiplying the circulating current adjustment coefficient by the circulating current allowable threshold corresponding to each battery device.

[0130] In the technical solution provided in this application embodiment, cell voltage balancing in the battery device is a key link to ensure the stable operation of the energy storage device. When the cell voltage in the battery device reaches a balanced state, it can avoid overcharging or over-discharging of individual cells, which would affect the overall performance of the battery device. When the circulating current cutoff time is long, the circulating current allowable threshold is determined as the circulating current critical threshold, so as not to affect the duration of the circulating current. When the circulating current cutoff time is short, the circulating current allowable threshold is adjusted by the circulating current adjustment coefficient, which can reduce the circulating current critical threshold, thereby further reducing the circulating current of the energy storage device and improving the reliability of the battery device operation in the energy storage device.

[0131] In some embodiments, when the energy storage device is shut down for charging or discharging, controlling the direct charging circuit connecting each battery device in the energy storage device to the busbar module to be turned on includes: when the energy storage device is shut down for charging or discharging, acquiring the voltage values ​​of multiple battery devices in the energy storage device; and when the difference between the maximum voltage value and the minimum voltage value among the voltage values ​​of the multiple battery devices is less than a preset voltage threshold, controlling the direct charging circuit connecting each battery device in the energy storage device to the busbar module to be turned on.

[0132] The voltage values ​​of multiple battery devices in an energy storage device can be detected by a voltage detection device. For example, the control device can obtain the voltage values ​​of multiple battery devices in the energy storage device from multiple controllers. The voltage value of the corresponding battery device obtained by each controller can be output to each controller by a voltage detection device set at the positive terminal of the corresponding battery device.

[0133] For example, different battery devices may have the same preset voltage threshold. For example, the preset voltage threshold may be a threshold pre-configured in the control device.

[0134] In the technical solution provided in this application embodiment, if the voltage difference between battery devices is too large, forcibly turning on the direct charging circuit may lead to excessive circulating current, causing problems such as heat generation and component loss. However, when the voltage difference is less than the preset voltage threshold, the voltage of each battery device is in a relatively balanced state. At this time, turning on the direct charging circuit can avoid the risk of abnormal circulating current caused by voltage imbalance, effectively prevent the safety hazards caused by turning on the direct charging circuit due to excessive voltage difference of battery devices after the charging and discharging is cut off, and improve the operational reliability of the energy storage device.

[0135] In some embodiments, the method further includes: when the difference between the maximum voltage value and the minimum voltage value is greater than or equal to a preset voltage threshold, determining at least two designated battery devices that need to be balanced based on the maximum voltage value, the minimum voltage value, and characteristic values ​​of the voltages of the plurality of battery devices; and controlling the direct charging circuit of the at least two designated battery devices to be turned on so that the difference between the maximum voltage value and the minimum voltage value is less than the preset voltage threshold.

[0136] For example, the characteristic values ​​of the voltages of the multiple battery devices may include at least one of the following: the maximum value, minimum value, median value, and average voltage value of the voltages of the multiple battery devices.

[0137] Among at least two specified battery devices that need to be balanced, the difference between the maximum and minimum voltage values ​​is less than a preset voltage threshold. These at least two specified battery devices can be either the two with the highest voltage values ​​or the two with the lowest voltage values ​​among a plurality of battery devices.

[0138] Specifically, by activating the direct charging circuits of at least two designated battery devices, the voltages of the at least two designated battery devices are balanced.

[0139] In some implementations, the number of designated battery devices can be determined by subtracting a preset voltage threshold from the difference between the maximum and minimum voltage values. For example, a larger result indicates a larger number of designated battery devices, and a smaller result indicates a smaller number of designated battery devices.

[0140] In other embodiments, control can be performed in multiple rounds: In the i-th round, the i+1 battery devices with the highest voltage are identified as the designated battery devices for the current round, and the direct charging circuit of the designated battery devices for the current round is controlled to be turned on. If the difference between the maximum voltage value and the minimum voltage value is less than a preset voltage threshold, the direct charging circuit connecting each battery device in the energy storage device and the busbar module is turned on. If the difference between the maximum voltage value and the minimum voltage value is still greater than or equal to the preset voltage threshold, the control of the direct charging circuit of the designated battery devices in the next round is continued.

[0141] In the technical solution provided in this application embodiment, the designated battery devices that need to be balanced are determined based on the maximum voltage value, the minimum voltage value, and the characteristic values ​​of the voltages of multiple battery devices. Only their direct charging circuits are turned on, allowing energy to flow directionally between these designated battery devices. The energy of the high-voltage designated battery device is transferred to the low-voltage designated battery device through the busbar module, thereby reducing the voltage difference between at least two designated battery devices. This creates conditions for the conduction control of the direct charging circuit connecting each battery device and the busbar module in the energy storage device, improving the operational reliability of the energy storage device.

[0142] In some embodiments, the characteristic values ​​of the voltages of the plurality of battery devices include the average voltage value of the voltages of the plurality of battery devices; determining at least two designated battery devices that need to be balanced based on the maximum voltage value, the minimum voltage value, and the characteristic values ​​of the voltages of the plurality of battery devices includes: determining at least two battery devices with the highest voltage values ​​among the plurality of battery devices as at least two designated battery devices when the difference between the maximum voltage value and the average voltage value is greater than the difference between the average voltage value and the minimum voltage value; and determining at least two battery devices with the lowest voltage values ​​among the plurality of battery devices as at least two designated battery devices when the difference between the maximum voltage value and the average voltage value is less than or equal to the difference between the average voltage value and the minimum voltage value.

[0143] When the difference between the maximum voltage value and the average voltage value is greater, it indicates that the voltage imbalance is mainly due to the excessively high voltage of individual battery devices. In this case, designating at least two battery devices with the highest voltage as designated battery devices and connecting their direct charging circuits can concentrate and guide the energy transfer of the excessively high voltage battery devices, quickly reduce the excessively high voltage in the battery devices, and avoid the risk of overcharging the cells in the battery devices due to excessively high voltage.

[0144] When the difference between the average voltage and the minimum voltage is greater, it indicates that the voltage imbalance is mainly caused by the low voltage of some battery devices. Designating at least two battery devices with the lowest voltage as designated battery devices and connecting their direct charging circuits can concentrate and guide the energy transfer of the low-voltage battery devices, quickly increase the low voltage in the battery devices, and avoid the risk of over-discharge of the cells in the battery devices caused by the low voltage.

[0145] For example, if the difference between the maximum voltage value and the average voltage value is greater than the difference between the average voltage value and the minimum voltage value, the K / 2 (e.g., the floor value of K / 2) battery devices with the highest voltage values ​​among the multiple battery devices are identified as at least two designated battery devices. Here, K is the total number of battery devices in the energy storage device. For example, if the difference between the maximum voltage value and the average voltage value is less than or equal to the difference between the average voltage value and the minimum voltage value, the K / 2 (e.g., the floor value of K / 2) battery devices with the lowest voltage values ​​among the multiple battery devices are identified as at least two designated battery devices.

[0146] In the technical solution provided in this application embodiment, the dominant factor of voltage imbalance between battery devices is determined based on the difference between the maximum voltage value and the average voltage value, and the difference between the average voltage value and the minimum voltage value. Based on the dominant factor of voltage imbalance between battery devices, a specific battery device is determined, which avoids the inability to quickly achieve the goal of the difference between the maximum voltage value and the minimum voltage value being less than the preset voltage threshold due to unclear balancing direction, thereby improving the accuracy of voltage regulation of battery devices in energy storage devices.

[0147] Figure 6 A flowchart illustrating a method for determining a target battery device provided in some embodiments, such as... Figure 6 As shown, this method is an explanation of the method described in the above embodiment for determining a target battery device from multiple battery devices in an energy storage device based on the circulating current critical threshold and the current value of each battery device. This method is applied to a control device in an energy storage device and includes:

[0148] S601. Obtain the charging and discharging status of each battery device and the current status data of each battery device; the current status data includes the current temperature and the current state of charge.

[0149] The explanation of S601 can be found in the description of the above embodiments, and will not be repeated here.

[0150] S602. Determine the maximum operating current value of each battery device based on the charging and discharging status of each battery device and the current status data of each battery device.

[0151] Among them, the maximum operating current value of each battery device is greater than the critical threshold of circulating current of each battery device.

[0152] For example, the controller may internally store a maximum charging current meter that matches the charging state and a maximum discharging current meter that matches the discharging state.

[0153] In some embodiments, S602 may include the following steps: for any battery device in a charging state, the control device may obtain a maximum charging current meter matching the charging state from internal storage, the maximum charging current meter including a maximum charging current value matching each of a plurality of temperatures and each of a plurality of states of charge respectively; from the maximum charging current meter, determine a maximum operating current value matching the current state data of the battery device in that charging state.

[0154] In some embodiments, S602 may include the following steps: for any battery device in a discharge state, the control device may obtain a maximum discharge current meter matching the discharge state from internal storage, the maximum discharge current meter including maximum discharge current values ​​matching each of a plurality of temperatures and each of a plurality of states of charge respectively; from the maximum discharge current meter, determine a maximum operating current value matching the current state data of the battery device in that discharge state.

[0155] For example, the maximum charging current meter can be in a similar form to the charging circulating current threshold table matching the charging state in Table 1 above, where the current value for each charging state in the maximum charging current meter is greater than the current value for each charging state in the charging circulating current threshold table matching the charging state in Table 1 above. Similarly, the maximum discharging current meter can be in a similar form to the discharging circulating current threshold table matching the discharging state in Table 2 above, where the current value for each discharging state in the maximum discharging current meter is greater than the current value for each discharging state in the discharging circulating current threshold table matching the discharging state in Table 2 above.

[0156] S603. Based on the circulating current critical threshold and the maximum operating current value of each battery device, determine the target battery device from multiple battery devices in the energy storage device.

[0157] In some embodiments, S603 may include the following steps: determining at least one candidate battery device from each battery device in the energy storage device whose current value is greater than or equal to the corresponding maximum charging current value; determining at least one predetermined battery device from each battery device in the energy storage device whose current value is greater than the corresponding circulating current critical threshold and less than the corresponding maximum charging current value; and determining at least one candidate battery device from at least one predetermined battery device based on the current state data of the cells in the predetermined battery device.

[0158] For example, from at least one predetermined battery device, a battery device that satisfies at least one of the following is determined as at least one candidate battery device: at least one cell in the battery device has a health state below a health state threshold; at least one cell in the battery device has a temperature above a preset temperature threshold; at least one cell in the battery device has a state of charge above a high state of charge threshold; at least one cell in the battery device has a state of charge below a low state of charge threshold; at least one candidate battery device and at least one alternative battery device are combined to obtain a target battery device.

[0159] In the technical solution provided in this application embodiment, the target battery device is not only selected from multiple battery devices based on the circulating current critical threshold of each battery device, but also selected from multiple battery devices based on the maximum operating current value of each battery device. This avoids the problem of inaccurate determination of the target battery device that needs current adjustment from multiple battery devices in the energy storage device by using a single threshold, and improves the accuracy of the determined target battery device that needs current adjustment.

[0160] In some embodiments, from the battery devices in the energy storage device, at least one candidate battery device is determined whose current value is greater than the circulating current critical threshold of each battery device and less than the maximum operating current value of each battery device, and whose state of charge meets the equalization processing conditions; from the multiple battery devices in the energy storage device, at least one alternative battery device is determined whose current value is greater than or equal to the maximum operating current value of each battery device; and at least one candidate battery device and at least one alternative battery device are merged to obtain the target battery device.

[0161] In the energy storage device, if there is at least one candidate battery device but no at least one alternative battery device, then at least one candidate battery device is identified as the target battery device; if there is no at least one candidate battery device but at least one alternative battery device, then at least one alternative battery device is identified as the target battery device.

[0162] In the technical solution provided in this application embodiment, a target battery device is obtained by merging at least one candidate battery device and at least one alternative battery device. Thus, the target battery device covers both battery devices with high current that require state-of-charge balancing and battery devices with current exceeding the maximum operating current. This not only avoids the problem of overcharging or over-discharging of at least one cell in the battery device, but also avoids the problem of cell failure caused by the operating current of the cell in the battery device exceeding the maximum operating current, thereby improving the reliability of the battery device operation in the energy storage device.

[0163] In some embodiments, the equalization processing condition includes: the difference between the maximum state of charge and the minimum state of charge among the multiple cells in the battery device is greater than or equal to a preset state of charge.

[0164] For example, the preset state of charge can be preset and configured in the control device.

[0165] In some embodiments, the equalization processing conditions include: the charge / discharge state of the battery device is a charging state, and the difference between the fully charged state and the maximum state of charge among the multiple cells in the battery device is less than or equal to a specified state of charge.

[0166] The fully charged state can be 100% charged. For example, the specified charged state can be preset and configured in the control device. For example, the value range of the specified charged state can be greater than 0% charged state and less than or equal to 10% charged state. For instance, the specified charged state can be 1% charged state, 2% charged state, 5% charged state, or 10% charged state, etc.

[0167] In some embodiments, the equalization processing conditions include: the charge / discharge state of the battery device is a discharge state, and the difference between the minimum state of charge and the zero state of charge among the multiple cells in the battery device is less than or equal to a specified state of charge.

[0168] Among them, the zero-charge state can be the 0% charge state.

[0169] In the technical solution provided in this application embodiment, when the difference between the maximum and minimum state of charge of multiple cells in a battery device is greater than or equal to a preset state of charge, it indicates that the cells in the battery device are prone to overcharging and over-discharging risks. In the charging state, when the difference between the full state of charge and the maximum state of charge among the multiple cells in the battery device is less than or equal to a specified state of charge, it indicates that some cells are close to being fully charged and are prone to overcharging risks. In the discharging state, if the difference between the minimum state of charge and the zero state of charge among the multiple cells in the battery device is less than or equal to a specified state of charge, it indicates that some cells are close to being discharged and are prone to over-discharging risks. This reduces the operating current of the target battery device that is prone to overcharging or over-discharging risks, allowing the target battery device sufficient time to equalize the state of charge of the included cells, thereby improving the risk of overcharging or over-discharging of cells in the energy storage device and improving the operational reliability of the energy storage device.

[0170] Figure 7 A flowchart illustrating a method for determining a target pre-charge circuit provided in some embodiments, such as... Figure 6 As shown, this method is applied to the control equipment in an energy storage device, and the method includes:

[0171] S701. Determine the balancing time of the cells in the target battery device based on the obtained state of charge of multiple cells in the target battery device.

[0172] In some implementations, the balancing time of the cells in the target battery device can be determined based on the state of charge (SBC) difference between the maximum and minimum SBCs among multiple cells in the target battery device. For example, the larger the SBC difference, the longer the balancing time of the cells in the target battery device. For example, the balancing time of the cells in the target battery device can be determined based on the resistance value of the balancing resistor used to balance the SBCs, and the SBC difference.

[0173] S702. Determine the required resistance value of the pre-charging circuit corresponding to the target battery device based on the equalization time of the cells in the target battery device.

[0174] The longer the balancing time of the cells in the target battery device, the lower the degree of balancing of the cells in the target battery device, and the more easily the cells in the target battery device are overcharged or over-discharged, thus determining the larger the required resistance value of the pre-charging circuit corresponding to the target battery device.

[0175] For example, a correspondence between multiple balancing durations and multiple required resistance values ​​can be obtained. Based on this correspondence and the balancing duration of the cells in the target battery device, the required resistance value of the pre-charging circuit corresponding to the target battery device can be determined. The correspondence between the multiple balancing durations and multiple required resistance values ​​can be either many-to-one or one-to-one.

[0176] S703. Determine the target pre-charge circuit from at least one pre-charge circuit based on the required resistance value of the pre-charge circuit corresponding to the target battery device.

[0177] The target pre-charging circuit can be one of at least one pre-charging circuits, or it can be multiple pre-charging circuits among at least one pre-charging circuits.

[0178] For example, the resistance value of the target pre-charging circuit can be greater than or equal to the required resistance value of the pre-charging circuit, and the target pre-charging circuit is the pre-charging circuit whose equivalent resistance value is closest to the required resistance value of the pre-charging circuit among at least one or more combinations of pre-charging circuits. For example, if the required resistance value of the pre-charging circuit corresponding to the target battery device is 24 ohms, and at least one pre-charging circuit includes pre-charging circuit 1 (with a resistance value of 50 ohms) and pre-charging circuit 2 (with a resistance value of 50 ohms), then the target pre-charging circuit includes pre-charging circuit 1 and pre-charging circuit 2.

[0179] When there is only one target pre-charging circuit, the resistance value of the target pre-charging circuit can be the resistance value of the pre-charging resistor in that single pre-charging circuit. When there are multiple target pre-charging circuits, the resistance value of the target pre-charging circuit can be the equivalent resistance value of the pre-charging resistors in each pre-charging circuit connected in parallel.

[0180] In the technical solution provided in this application embodiment, the required resistance value of the pre-charging circuit corresponding to the target battery device is determined based on the equalization time of the cells in the target battery device. Then, based on the required resistance value of the pre-charging circuit corresponding to the target battery device, a target pre-charging circuit is determined from at least one pre-charging circuit. The selected target pre-charging circuit can provide appropriate current limiting, which will not lead to a small current in the target battery device due to an excessively large resistance value of the target pre-charging circuit, thus causing low voltage equalization efficiency between battery devices, thereby improving the voltage equalization efficiency between battery devices and reducing energy loss. Conversely, it will not lead to a large current in the target battery device due to an excessively small resistance value of the target pre-charging circuit, thus causing overcharging or over-discharging of the cells in the battery device, thereby improving the operational reliability of the energy storage device.

[0181] During the operation of energy storage devices, circulating currents can easily occur due to voltage differences or parameter inconsistencies among multiple parallel battery devices. Circulating currents can lead to overcharging or over-discharging of cells and may also cause frequent power-offs in the battery devices, severely impacting the stability and reliability of the energy storage device. To address this technical problem, this application proposes a circulating current optimization method. By dynamically adjusting the magnitude of the circulating current and optimizing the circulating current process, the duration of the circulating current is significantly extended, providing more opportunities for cell balancing within the battery device, thereby improving the stability of the energy storage device and the lifespan of the cells.

[0182] In related technologies, during the operation of multi-parallel battery devices, due to inconsistent cell capacity or limitations of control strategies, circulating currents are easily generated between battery devices. Circulating currents can cause some cells to be overcharged or over-discharged, thereby shortening cell life and reducing system reliability. When the circulating current is too large, the control equipment may forcibly disconnect the direct charging circuit of the battery device, such as the main positive relay in the direct charging circuit, causing the battery device to frequently power down, which seriously affects the continuous operation capability and stability of the energy storage device.

[0183] The core of this application's embodiment lies in the real-time monitoring of the circulating current between parallel battery devices through a battery management system (BMS, i.e., the aforementioned control device), combined with the control of a pre-charge relay and a main positive relay. The pre-charge relay is used to control the pre-charge circuit, and the main positive relay is used to control the direct charging circuit, dynamically adjusting the circulating current magnitude and optimizing the circulating current process.

[0184] The embodiments of this application can achieve circulating current optimization through the following technical means: (1) When the circulating current exceeds the preset threshold (i.e., the above-mentioned circulating current critical threshold), the BMS controls the closing of the pre-charge relay and the opening of the main positive relay, and connects the pre-charge resistor to the battery device circuit, thereby reducing the circulating current value and effectively controlling the risk of overcharging or over-discharging of the battery cell. (2) When the circulating current returns to zero, the BMS controls the opening of the pre-charge relay and the closing of the main positive relay, restoring the normal operation state of the battery device.

[0185] The above methods can achieve the following technical effects: (1) Controlling the circulating current: By connecting a pre-charge resistor, the circulating current value is reduced, thereby effectively controlling the risk of overcharging or over-discharging of the battery cell. (2) Extending the duration of the circulating current: Optimizing the circulating current process and extending the duration of the circulating current provides more opportunities for the depolarization of the battery cell to achieve equilibrium and alleviate the problem of inconsistent capacity. (3) Improving system stability: By dynamically adjusting the circulating current size, the problem of frequent power-off of the battery device caused by excessive circulating current is reduced, thereby improving the stability and reliability of the energy storage device.

[0186] In some embodiments, the circulating current critical threshold can be dynamically adjusted. For example, the circulating current detection threshold can be dynamically adjusted based on the operating status of the battery device and historical circulating current data to further optimize the accuracy and efficiency of circulating current processing.

[0187] In some embodiments, a prioritization mechanism for circulating current processing is proposed. Specifically, when the power conversion system (PCS) requests zero power (i.e., the energy storage device is either charging or discharging off), the circulating current processing flow is executed first to ensure the efficiency of the circulating current optimization process without affecting the charging and discharging operation of the energy storage device.

[0188] The following technical effects can be achieved through the above methods: (1) Dynamic adjustment of the circulating current critical threshold: The circulating current critical threshold is dynamically adjusted according to the operating status of the battery device and the historical data of the circulating current, so as to further optimize the accuracy and efficiency of the circulating current processing. (2) Priority mechanism for circulating current processing: When the power requested by the PCS is zero, the circulating current processing process is executed first to ensure the efficiency of the circulating current optimization process, while not affecting the normal operation of the system. (3) Balancing opportunities among battery devices: When the energy storage device is cut off from charging or discharging, the duration of the circulating current is extended to provide more opportunities for energy balancing among the battery devices, thereby improving the overall capacity utilization of the system.

[0189] In some embodiments, in the implementation of circulating current detection and judgment, when the energy storage device is off-charge / discharge, the BMS collects the current value of each battery device in real time through a current sensor. When the current value of a battery device is detected to exceed a preset threshold (e.g., 10A), the BMS confirms that there is a large circulating current.

[0190] In some embodiments, the control logic for the pre-charge relay and the main positive relay is as follows: When the circulating current exceeds a threshold, the BMS issues a control command to close the pre-charge relay and disconnect the main positive relay. At this time, the pre-charge resistor is connected to the battery device circuit to reduce the circulating current value. The BMS continuously monitors the magnitude of the circulating current. When the circulating current returns to zero, the BMS controls the disconnection of the pre-charge relay and the closure of the main positive relay, restoring the normal operating state of the battery device.

[0191] In some embodiments, the rapid response mechanism for PCS power requests is as follows: If the PCS power request is not zero, the BMS prioritizes closing the main positive relay and opening the pre-charge relay to ensure that the system can quickly respond to power demands. If the PCS power request is zero, the BMS prioritizes executing the circulating current processing procedure to optimize the circulating current process.

[0192] In some embodiments, a priority mechanism for recirculation processing is proposed:

[0193] (1) Dynamic adjustment algorithm for circulating current detection threshold: The circulating current detection threshold is dynamically adjusted based on the operating status of the battery device and historical circulating current data (reflecting the capacity decay and aging degree of the battery cells). For example, when the temperature of the battery device is high or the SOC (State of Charge) is low, the circulating current detection threshold can be appropriately reduced to improve the sensitivity of circulating current processing.

[0194] (2) Priority strategy for circulating current processing: When the PCS requests zero power, the circulating current processing procedure is executed first to ensure the efficiency of the circulating current optimization process. In addition, different priorities (thresholds) can be set according to the operating status of the battery device and the historical circulating current data to further optimize the efficiency and effect of circulating current processing.

[0195] In some embodiments, extending the circulation duration provides more opportunities for energy balancing among the battery devices, thereby improving the overall capacity utilization of the system.

[0196] Based on the same inventive concept, this application also provides an energy storage device regulating apparatus for implementing the regulating method of the energy storage device described above. The solution provided by this apparatus is similar to the solution described in the above method; therefore, the specific limitations in one or more energy storage device regulating apparatus embodiments provided below can be found in the limitations of the energy storage device regulating method described above, and will not be repeated here.

[0197] In one exemplary embodiment, Figure 8 A schematic diagram of the regulating device of the energy storage device provided in some embodiments, such as Figure 8 As shown, the regulating device 800 of the energy storage device includes:

[0198] The control module 801 is used to control the direct charging circuit connecting each battery device in the energy storage device to the combiner module to be turned on when the charging or discharging of the energy storage device is cut off; the direct charging circuit is connected in parallel with at least one pre-charging circuit, and the resistance of the pre-charging circuit is greater than the resistance of the direct charging circuit.

[0199] The acquisition module 802 is used to acquire the current value of each battery device in the energy storage device;

[0200] The determination module 803 is used to determine the target battery device from multiple battery devices in the energy storage device based on the circulating current critical threshold of each battery device and the current value of each battery device; the circulating current critical threshold of each battery device is determined based on the charging and discharging state of each battery device and the current state data of each battery device.

[0201] The control module 801 is also used to control the conduction of the target pre-charging circuit corresponding to the target battery device and the disconnection of the target direct charging circuit corresponding to it.

[0202] In some embodiments, the control module 801 is further configured to control the target direct charging circuit corresponding to the target battery device to be turned on and the target pre-charging circuit to be turned off when the current value of the target battery device drops to the circulating current setting threshold.

[0203] In some embodiments, the determining module 803 includes a state acquisition unit, a circulating current allowable threshold determining unit, and a circulating current critical threshold determining unit; the state acquisition unit is used to acquire the charge / discharge state of each battery device and the current state data of each battery device; the current state data includes the current temperature and the current state of charge; the circulating current allowable threshold determining unit is used to determine the circulating current allowable threshold corresponding to each battery device based on the charge / discharge state of each battery device and the current state data of each battery device; the circulating current critical threshold determining unit is used to determine the circulating current critical threshold of each battery device based on the acquired circulating current cutoff time and the circulating current allowable threshold corresponding to each battery device.

[0204] In some embodiments, the circulating current allowable threshold determination unit is further configured to: determine the health status data of each battery device based on the acquired historical operating status data of each battery device; determine a circulating current threshold table that matches both the charge / discharge state of each battery device and the health status data of each battery device; the circulating current threshold table includes current values ​​that match each of a plurality of temperatures and each of a plurality of states of charge; and determine the current values ​​in the circulating current threshold table that match the current status data of each battery device as the circulating current allowable threshold corresponding to each battery device.

[0205] In some embodiments, the current temperature of each battery device includes the current maximum temperature and the current minimum temperature of the cells in each battery device; the current state of charge of each battery device includes the current maximum state of charge and the current minimum state of charge of the cells in each battery device; the circulating current allowable threshold determination unit is further configured to: determine, from a circulating current threshold table, a first current value matching the current maximum temperature and the current maximum state of charge, a second current value matching the current maximum temperature and the current minimum state of charge, a third current value matching the current minimum temperature and the current maximum state of charge, and a fourth current value matching the current minimum temperature and the current minimum state of charge; and determine the minimum current value among the first current value, the second current value, the third current value, and the fourth current value as the circulating current allowable threshold corresponding to each battery device.

[0206] In some embodiments, the circulating current critical threshold determination unit is further configured to: obtain the charge / discharge cutoff duration of the energy storage device when charging or discharging is cut off; when the circulating current cutoff duration is greater than or equal to the charge / discharge cutoff duration, determine the circulating current allowable threshold corresponding to each battery device as the circulating current critical threshold of each battery device; when the circulating current cutoff duration is less than the charge / discharge cutoff duration, determine the circulating current adjustment coefficient based on the circulating current cutoff duration and the charge / discharge cutoff duration, and adjust the circulating current allowable threshold corresponding to each battery device using the circulating current adjustment coefficient to obtain the circulating current critical threshold of each battery device.

[0207] In some embodiments, the control module 801 includes a voltage acquisition unit and a control unit. The voltage acquisition unit is used to acquire the voltage values ​​of multiple battery devices in the energy storage device when the charging or discharging of the energy storage device is cut off. The control unit is used to control the direct charging circuit connecting each battery device in the energy storage device to the busbar module to be turned on when the difference between the maximum voltage value and the minimum voltage value among the voltage values ​​of the multiple battery devices is less than a preset voltage threshold.

[0208] In some embodiments, the control module 801 further includes a designated battery device determination unit; the designated battery device determination unit is configured to determine at least two designated battery devices that need to be balanced based on the maximum voltage value, the minimum voltage value, and the characteristic values ​​of the voltages of the multiple battery devices when the difference between the maximum voltage value and the minimum voltage value is greater than or equal to a preset voltage threshold; the control unit is further configured to control the direct charging circuit of at least two designated battery devices to be turned on so that the difference between the maximum voltage value and the minimum voltage value is less than the preset voltage threshold.

[0209] In some embodiments, the characteristic values ​​of the voltages of the plurality of battery devices include the average voltage value of the voltages of the plurality of battery devices; the designated battery device determining unit is further configured to: determine at least two battery devices with the highest voltage values ​​among the plurality of battery devices as at least two designated battery devices when the difference between the maximum voltage value and the average voltage value is greater than the difference between the average voltage value and the minimum voltage value; and determine at least two battery devices with the lowest voltage values ​​among the plurality of battery devices as at least two designated battery devices when the difference between the maximum voltage value and the average voltage value is less than or equal to the difference between the average voltage value and the minimum voltage value.

[0210] In some embodiments, the determining module 803 includes a state acquisition unit, a maximum operating current value determining unit, and a target battery device determining unit; the acquisition unit is used to acquire the charge / discharge state of each battery device and the current state data of each battery device; the current state data includes the current temperature and the current state of charge; the maximum operating current value determining unit is used to determine the maximum operating current value of each battery device based on the charge / discharge state of each battery device and the current state data of each battery device; the maximum operating current value of each battery device is greater than the circulating current critical threshold of each battery device; the target battery device determining unit is used to determine the target battery device from multiple battery devices in the energy storage device based on the circulating current critical threshold of each battery device and the maximum operating current value of each battery device.

[0211] In some embodiments, the target battery device determination unit is further configured to: determine, from the battery devices in the energy storage device, at least one candidate battery device whose current value is greater than the circulating current critical threshold of each battery device and less than the maximum operating current value of each battery device, and whose state of charge meets the equalization processing conditions; determine, from the plurality of battery devices in the energy storage device, at least one alternative battery device whose current value is greater than or equal to the maximum operating current value of each battery device; and merge at least one candidate battery device and at least one alternative battery device to obtain the target battery device.

[0212] In some embodiments, the equalization processing conditions include at least one of the following: the difference between the maximum and minimum states of charge among the multiple cells in the battery device is greater than or equal to a preset state of charge; the charge / discharge state of the battery device is a charging state, and the difference between the fully charged state and the maximum state of charge among the multiple cells in the battery device is less than or equal to a specified state of charge; the charge / discharge state of the battery device is a discharging state, and the difference between the minimum state of charge and the zero state of charge among the multiple cells in the battery device is less than or equal to a specified state of charge.

[0213] In some embodiments, the determining module 803 includes an balancing duration determining unit, a demand resistance determining unit, and a target pre-charging circuit determining unit. The balancing duration determining unit is used to determine the balancing duration of the cells in the target battery device based on the obtained state of charge of multiple cells in the target battery device. The demand resistance determining unit is used to determine the demand resistance of the pre-charging circuit corresponding to the target battery device based on the balancing duration of the cells in the target battery device. The target pre-charging circuit determining unit is used to determine a target pre-charging circuit from at least one pre-charging circuit based on the demand resistance of the pre-charging circuit corresponding to the target battery device.

[0214] The descriptions of the above device embodiments are similar to those of the above method embodiments, and have similar beneficial effects. For technical details not disclosed in the device embodiments of this application, please refer to the descriptions of the method embodiments of this application for understanding.

[0215] Each module in the regulating device of the aforementioned energy storage device can be implemented entirely or partially through software, hardware, or a combination thereof. These modules can be embedded in the processor of the control device in hardware form or independent of it, or stored in the memory of the control device in software form, so that the processor can call and execute the operations corresponding to each module.

[0216] In one exemplary embodiment, Figure 9This is a schematic diagram of a control device provided for some embodiments. The control device includes a processor, a memory, an input / output interface, a communication interface, a display unit, and an input device. The processor, memory, and input / output interface are connected via a system bus, and the communication interface, display unit, and input device are also connected to the system bus via the input / output interface. The processor of the control device provides computing and control capabilities. The memory of the control device includes a non-volatile storage medium and internal memory. The non-volatile storage medium stores an operating system and computer programs. The internal memory provides an environment for the operation of the operating system and computer programs in the non-volatile storage medium. The input / output interface of the control device is used for exchanging information between the processor and external devices. The communication interface of the control device is used for wired or wireless communication with external terminals. Wireless communication can be achieved through Wireless Fidelity (WIFI), mobile cellular networks, Near Field Communication (NFC), or other technologies. When the computer program is executed by the processor, it implements a method for regulating an energy storage device. The display unit of the control device is used to form a visually visible image and can be a display screen, a projection device, or a virtual reality imaging device. The display screen can be an LCD screen or an e-ink screen. The input device of the control device can be a touch layer covering the display screen, or buttons, trackballs, or touchpads set on the housing of the control device, or external keyboards, touchpads, or mice, etc.

[0217] Those skilled in the art will understand that Figure 9 The structure shown is merely a block diagram of a portion of the structure related to the present application and does not constitute a limitation on the control device to which the present application is applied. The specific control device may include more or fewer components than those shown in the figure, or combine certain components, or have different component arrangements.

[0218] For example, the control device includes a memory and a processor, the memory storing a computer program, and the processor executing the computer program to implement the steps of the method of any of the above embodiments.

[0219] In one embodiment, a computer-readable storage medium is provided, wherein a computer program, when executed by a processor, implements the steps of the method provided in any of the above embodiments.

[0220] In one embodiment, a computer program product is provided, including a computer program that, when executed by a processor, implements the steps of the method provided in any of the above embodiments.

[0221] Those skilled in the art will understand that all or part of the processes in the methods of the above embodiments can be implemented by a computer program instructing related hardware. The computer program can be stored in a non-volatile computer-readable storage medium. When the computer program is executed, it can include the processes of the embodiments of the methods described above.

[0222] The processor, functional modules, or functional units in any embodiment of this application may include an integration of one or more of the following: a general-purpose processor, an application-specific integrated circuit (ASIC), a digital signal processor (DSP), a digital signal processing device (DSPD), a programmable logic device (PLD), a field-programmable gate array (FPGA), a central processing unit (CPU), a graphics processing unit (GPU), an embedded neural network processing unit (NPU), a controller, a microcontroller, a microprocessor, a programmable logic device, a discrete gate or transistor logic device, a discrete hardware component, a quantum computing-based data processing logic unit, an artificial intelligence (AI) processor, etc. The general-purpose processor may be a microprocessor or any conventional processor.

[0223] The memory or computer-readable storage medium in any embodiment of this application may include at least one of non-volatile memory and volatile memory. Non-volatile memory includes integration of one or more of the following: Read Only Memory (ROM), Programmable Read-Only Memory (PROM), Erasable Programmable Read-Only Memory (EPROM), Electrically Erasable Programmable Read-Only Memory (EEPROM), Ferromagnetic Random Access Memory (FRAM), Flash Memory, Magnetic Surface Memory, Optical Disc, Compact Disc Read-Only Memory (CD-ROM), Magnetic Tape, Floppy Disk, Flash Memory, Optical Memory, High-Density Embedded Non-Volatile Memory, Resistive Random Access Memory (ReRAM), Magnetoresistive Random Access Memory (MRAM), Ferroelectric Random Access Memory (FRAM), Phase Change Memory (PCM), Graphene Memory, Volatile Memory, etc. Volatile memory includes one or more of the following: Random Access Memory (RAM) or external cache memory. By way of illustration and not limitation, RAM can take many forms, such as Static Random Access Memory (SRAM) or Dynamic Random Access Memory (DRAM).

[0224] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this application.

[0225] The above embodiments are merely illustrative of several implementation methods of this application, and their descriptions are relatively specific and detailed. However, they should not be construed as limiting the scope of this application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this application should be determined by the appended claims.

Claims

1. A method for regulating an energy storage device, characterized in that, The method includes: When the energy storage device is shut down for charging or discharging, the direct charging circuit connecting each battery device in the energy storage device to the current combiner module is turned on, and the current value of each battery device in the energy storage device is obtained; the direct charging circuit is connected in parallel with at least one pre-charging circuit, and the resistance value of the pre-charging circuit is greater than the resistance value of the direct charging circuit. Based on the obtained charge / discharge state and current state data of each battery device, the maximum operating current value of each battery device is determined; the maximum operating current value of each battery device is greater than the circulating current critical threshold of each battery device; the current state data includes the current temperature and the current state of charge. Based on the circulating current critical threshold and the maximum operating current value of each battery device, a target battery device is determined from a plurality of battery devices in the energy storage device; the circulating current critical threshold of each battery device is determined based on the obtained circulating current cutoff time and the circulating current allowable threshold corresponding to each battery device; the circulating current allowable threshold corresponding to each battery device is determined based on the charging and discharging state of each battery device and the current state data of each battery device. Control the target pre-charging circuit corresponding to the target battery device to be turned on and the target direct charging circuit corresponding to be turned off.

2. The method according to claim 1, characterized in that, The method further includes: When the current value of the target battery device drops to the circulating current setting threshold, the target direct charging circuit corresponding to the target battery device is turned on and the target pre-charging circuit is turned off.

3. The method according to claim 1 or 2, characterized in that, The method further includes: Obtain the charging / discharging status of each battery device and the current status data of each battery device; Based on the charging and discharging state of each battery device and the current state data of each battery device, determine the circulating current allowable threshold corresponding to each battery device; Based on the obtained circulating current cutoff time and the circulating current allowable threshold corresponding to each battery device, the circulating current critical threshold of each battery device is determined.

4. The method according to claim 3, characterized in that, The step of determining the circulating current allowable threshold for each battery device based on the charging / discharging state and current state data of each battery device includes: Based on the historical operating status data of each of the battery devices, determine the health status data of each of the battery devices; A circulating current threshold table is determined that matches the charge / discharge state and health status data of each of the battery devices; the circulating current threshold table includes current values ​​that match each of a plurality of temperatures and each of a plurality of states of charge. The current value that matches the current state data of each battery device in the circulating current threshold table is determined as the circulating current allowable threshold for each battery device.

5. The method according to claim 4, characterized in that, The current temperature of each battery device includes the current maximum temperature and the current minimum temperature of the cells in each battery device; the current state of charge of each battery device includes the current maximum state of charge and the current minimum state of charge of the cells in each battery device. The step of determining the current value matching the current state data of each battery device in the circulating current threshold table as the circulating current allowable threshold for each battery device includes: From the circulating current threshold table, determine a first current value that matches the current maximum temperature and the current maximum state of charge, a second current value that matches the current maximum temperature and the current minimum state of charge, a third current value that matches the current minimum temperature and the current maximum state of charge, and a fourth current value that matches the current minimum temperature and the current minimum state of charge. The minimum current value among the first current value, the second current value, the third current value, and the fourth current value is determined as the circulating current allowable threshold for each of the battery devices.

6. The method according to claim 3, characterized in that, The step of determining the critical threshold of the circulating current for each battery device based on the obtained circulating current cutoff time and the circulating current allowable threshold corresponding to each battery device includes: Obtain the charge / discharge cutoff duration of the energy storage device at the point where charging or discharging is cutoff. When the circulating current cutoff time is greater than or equal to the charge / discharge cutoff time, the circulating current allowable threshold corresponding to each battery device is determined as the circulating current critical threshold of each battery device. When the circulating current cutoff time is less than the charge / discharge cutoff time, a circulating current adjustment coefficient is determined based on the circulating current cutoff time and the charge / discharge cutoff time, and the circulating current allowable threshold corresponding to each battery device is adjusted using the circulating current adjustment coefficient to obtain the circulating current critical threshold of each battery device.

7. The method according to claim 1 or 2, characterized in that, When the energy storage device is shut down for charging or discharging, controlling the direct charging circuit connecting each battery device in the energy storage device to the combiner module to be turned on includes: When the energy storage device is shut down for charging or discharging, the voltage values ​​of multiple battery devices in the energy storage device are obtained. If the difference between the maximum and minimum voltage values ​​among the multiple battery devices is less than a preset voltage threshold, the direct charging circuit connecting each battery device in the energy storage device to the busbar module is activated.

8. The method according to claim 7, characterized in that, The method further includes: If the difference between the maximum voltage value and the minimum voltage value is greater than or equal to the preset voltage threshold, at least two specified battery devices that need to be balanced are determined based on the maximum voltage value, the minimum voltage value, and the characteristic values ​​of the voltages of the plurality of battery devices. Control the direct charging circuits of the at least two designated battery devices to make the difference between the maximum voltage value and the minimum voltage value less than the preset voltage threshold.

9. The method according to claim 8, characterized in that, The characteristic values ​​of the voltages of the plurality of battery devices include the average voltage value of the voltages of the plurality of battery devices; determining at least two specified battery devices that need to be balanced based on the maximum voltage value, the minimum voltage value, and the characteristic values ​​of the voltages of the plurality of battery devices includes: If the difference between the maximum voltage value and the average voltage value is greater than the difference between the average voltage value and the minimum voltage value, then at least two battery devices with the highest voltage values ​​among the plurality of battery devices are identified as the at least two designated battery devices. If the difference between the maximum voltage value and the average voltage value is less than or equal to the difference between the average voltage value and the minimum voltage value, then at least two battery devices with the lowest voltage values ​​among the plurality of battery devices are identified as the at least two designated battery devices.

10. The method according to claim 1 or 2, characterized in that, The step of determining a target battery device from a plurality of battery devices in the energy storage device based on the circulating current critical threshold and the maximum operating current value of each battery device includes: From the battery devices in the energy storage device, at least one candidate battery device with a current value greater than or equal to the corresponding maximum operating current value is determined, and at least one predetermined battery device with a current value greater than the corresponding circulating current critical threshold and less than the corresponding maximum operating current value is determined. Based on the current state data of the cells in the predetermined battery device, at least one candidate battery device is determined from the at least one predetermined battery device. The target battery device is obtained by merging the at least one candidate battery device and the at least one alternative battery device.

11. The method according to claim 1 or 2, characterized in that, The step of determining a target battery device from a plurality of battery devices in the energy storage device based on the circulating current critical threshold and the maximum operating current value of each battery device includes: From each of the battery devices in the energy storage device, at least one candidate battery device is determined whose current value is greater than the circulating current critical threshold of each battery device and less than the maximum operating current value of each battery device, and whose state of charge satisfies the equalization processing condition. From the plurality of battery devices in the energy storage device, at least one candidate battery device is determined whose current value is greater than or equal to the maximum operating current value of each of the battery devices. The target battery device is obtained by merging the at least one candidate battery device and the at least one alternative battery device.

12. The method according to claim 11, characterized in that, The equalization processing conditions include at least one of the following: The difference between the maximum and minimum states of charge of multiple cells in a battery device is greater than or equal to the preset state of charge. The charging and discharging state of the battery device is the charging state, and the difference between the fully charged state and the maximum state of charge among the multiple cells in the battery device is less than or equal to the specified state of charge. The charging and discharging state of the battery device is the discharge state, and the difference between the minimum state of charge and the zero state of charge among the multiple cells in the battery device is less than or equal to the specified state of charge.

13. The method according to claim 1 or 2, characterized in that, The method further includes: Based on the obtained state of charge of multiple cells in the target battery device, the equalization time of the cells in the target battery device is determined. Based on the equalization time of the cells in the target battery device, determine the required resistance value of the pre-charging circuit corresponding to the target battery device; The target pre-charge circuit is determined from the at least one pre-charge circuit based on the required resistance value of the pre-charge circuit corresponding to the target battery device.

14. A regulating device for an energy storage device, characterized in that, The regulating device of the energy storage device includes: The control module is used to control the direct charging circuit connecting each battery device in the energy storage device to the combiner module to be turned on when the charging or discharging of the energy storage device is cut off; the direct charging circuit is connected in parallel with at least one pre-charging circuit, and the resistance of the pre-charging circuit is greater than the resistance of the direct charging circuit. The acquisition module is used to acquire the current value of each battery device in the energy storage device; A determination module is used to determine the maximum operating current value of each battery device based on the acquired charge / discharge state and current state data of each battery device; the maximum operating current value of each battery device is greater than the circulating current critical threshold of each battery device; the current state data includes the current temperature and the current state of charge; a target battery device is determined from multiple battery devices in the energy storage device based on the circulating current critical threshold and the maximum operating current value of each battery device; the circulating current critical threshold of each battery device is determined based on the acquired circulating current cutoff time and the circulating current allowable threshold corresponding to each battery device; the circulating current allowable threshold corresponding to each battery device is determined based on the charge / discharge state and current state data of each battery device; The control module is also used to control the conduction of the target pre-charging circuit corresponding to the target battery device and the disconnection of the corresponding target direct charging circuit.

15. A control device comprising a memory and a processor, the memory storing a computer program, characterized in that, When the processor executes the computer program, it implements the steps of the method according to any one of claims 1 to 13.

16. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by a processor, it implements the steps of the method according to any one of claims 1 to 13.

17. A computer program product, comprising a computer program, characterized in that, When the computer program is executed by a processor, it implements the steps of the method according to any one of claims 1 to 13.

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