Lithium battery and lead-acid battery sharing system and method

Abstract

The invention provides a lithium battery and lead-acid battery sharing system and method. The system comprises an uninterruptible power supply, a lead-acid battery pack and a plurality of lithium battery units, the lead-acid battery pack is connected with the uninterruptible power supply and the plurality of lithium battery units; the lead-acid battery pack is used for providing standby power for the uninterruptible power supply; the lithium battery unit comprises a lithium battery pack and a direct current-direct current conversion circuit; and the direct current-direct current conversion circuit is used for performing voltage conversion on the electric energy output by the lithium battery pack, so that the lithium battery unit and the lead-acid battery pack are connected in parallel at the same discharge voltage, and standby power is provided for the uninterruptible power supply.

Description

Technical Field

[0001] This application relates to the field of uninterruptible power supply battery sharing, and more particularly to a system and method for sharing lithium batteries and lead-acid batteries. Background Technology

[0002] In uninterruptible power supply (UPS) systems, batteries serve as critical backup energy components, and their performance directly impacts the system's stability and reliability. Traditionally, lead-acid batteries have been widely used in UPS systems due to their low cost and mature technology; however, their drawbacks, such as low energy density and limited cycle life, have become increasingly apparent. In recent years, lithium batteries have become an important choice for backup power solutions in UPS systems due to their advantages such as high energy density, long cycle life, and lightweight design.

[0003] In related technologies, solutions for the mixed use of lithium batteries and lead-acid batteries typically employ independent configurations or time-sharing switching through complex control strategies to avoid system instability caused by voltage mismatch, thus failing to achieve efficient collaborative power supply between lithium batteries and lead-acid batteries. Summary of the Invention

[0004] This application provides a system and method for sharing lithium batteries and lead-acid batteries. By connecting multiple lithium battery cells and lead-acid battery packs in parallel for power supply, and using a DC-DC conversion circuit to achieve voltage matching and current control, the lithium battery cells and lead-acid battery packs can work together, improving the overall stability and reliability of power supply, while extending the service life of the lead-acid battery packs.

[0005] The technical solution of this application embodiment is implemented as follows: This application provides a system that combines lithium batteries and lead-acid batteries, the system comprising: An uninterruptible power supply (UPS), a lead-acid battery pack, and multiple lithium battery cells; the lead-acid battery pack is connected to the UPS and the multiple lithium battery cells; the lead-acid battery pack is used to provide backup power to the UPS. The lithium battery unit includes a lithium battery pack and a DC-DC conversion circuit; the DC-DC conversion circuit is used to convert the voltage of the electrical energy output by the lithium battery pack so that the lithium battery unit and the lead-acid battery pack can be connected in parallel with the same discharge voltage to provide backup power for the uninterruptible power supply.

[0006] In the above scheme, the lithium battery unit includes a controller, which is used to set the boost voltage value of the DC-DC conversion circuit in the lithium battery unit according to the nominal voltage value of the lead-acid battery pack, so that the lithium battery unit and the lead-acid battery pack are connected in parallel with the same discharge voltage to provide backup power for the uninterruptible power supply.

[0007] In the above scheme, the controller is used to connect the lithium battery cell and the lead-acid battery pack in parallel when the discharge voltage of the lead-acid battery pack reaches the boost voltage value, so as to provide backup power for the uninterruptible power supply.

[0008] In the above scheme, after the lithium battery unit and the lead-acid battery pack are connected in parallel, the controller is used to control the lithium battery unit to discharge, and during the discharge process of the lithium battery unit, to control the duty cycle or switching frequency of the DC-DC conversion circuit to limit the discharge current of the lead-acid battery pack.

[0009] In the above scheme, the controller is used to shut down the DC-DC conversion circuit when the discharge voltage of the lithium battery cell reaches the first undervoltage protection value.

[0010] In the above scheme, the controller is used to control the lead-acid battery to discharge after the DC-DC conversion circuit is turned off, until the discharge voltage of the lead-acid battery reaches the second undervoltage protection value.

[0011] In the above scheme, the controller is used to receive the current command sent by the uninterruptible power supply; the current command is used to control the discharge current of each lithium battery cell during the discharge process.

[0012] In the above scheme, the controller is used to adjust the discharge current of the second lithium battery unit during the discharge process based on the current command when the first lithium battery unit fails; the first lithium battery unit is any one of the plurality of lithium battery units; the second lithium battery unit is any one of the plurality of lithium battery units; the first lithium battery unit and the lithium battery units are different.

[0013] In the above scheme, the controller is used to control the uninterruptible power supply to precharge the lead-acid battery pack until the charging voltage of the lead-acid battery pack reaches the turn-on voltage value. After the charging voltage of the lead-acid battery pack reaches the threshold voltage, the uninterruptible power supply is controlled to charge the lithium battery pack and the lead-acid battery pack simultaneously. During the charging process of the lithium battery pack, the duty cycle or switching frequency of the DC-DC conversion circuit is controlled to limit the charging current of the lithium battery pack until the charging voltage of the lithium battery pack reaches the threshold voltage. After the charging voltage of the lithium battery pack reaches the activation voltage value, the uninterruptible power supply is controlled to continue charging the lead-acid battery pack until the charging voltage of the lead-acid battery pack reaches the float charge voltage value.

[0014] A method for using both lithium batteries and lead-acid batteries, applied to the aforementioned system using both lithium batteries and lead-acid batteries; the method includes: During the use of the lead-acid battery pack, the DC-DC conversion circuit in each lithium battery cell is controlled to convert the voltage of the electrical energy output by each lithium battery cell, so that the lithium battery cell and the lead-acid battery pack are connected in parallel with the same discharge voltage to provide backup power for the uninterruptible power supply.

[0015] This application provides an electronic device, including: a processor and a memory for storing computer programs capable of running on the processor. When the processor runs the computer program, it executes the method for sharing lithium batteries and lead-acid batteries provided in the embodiments of this application.

[0016] This application provides a computer-readable storage medium storing a computer program or computer-executable instructions for implementing the lithium battery and lead-acid battery sharing method provided in this application when executed by a processor.

[0017] This application provides a computer program product, including a computer program or computer-executable instructions. When the computer program or computer-executable instructions are executed by a processor, they implement the method for using both lithium batteries and lead-acid batteries provided in this application.

[0018] The embodiments of this application have the following beneficial effects: by connecting multiple lithium battery cells and lead-acid battery packs in parallel for power supply, and using a DC-DC conversion circuit to achieve voltage matching and current control, the lithium battery cells and lead-acid battery packs can work together, improving the overall stability and reliability of power supply, while extending the service life of the lead-acid battery packs. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of a shared lithium battery and lead-acid battery system provided in an embodiment of this application; Figure 2 This is a schematic diagram of another lithium battery and lead-acid battery shared system provided in an embodiment of this application; Figure 3 This is a schematic flowchart of a method for using both lithium batteries and lead-acid batteries, provided in an embodiment of this application. Figure 4 This is a schematic diagram of the structure of the electronic device provided in the embodiments of this application. Detailed Implementation

[0020] To make the objectives, technical solutions, and advantages of this application clearer, the application will be further described in detail below with reference to the accompanying drawings. The described embodiments should not be regarded as limitations on this application. All other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0021] In the following description, references are made to “some embodiments,” which describe a subset of all possible embodiments. However, it is understood that “some embodiments” may be the same subset or different subsets of all possible embodiments and may be combined with each other without conflict.

[0022] In the following description, the terms "first, second, third" are used merely to distinguish similar objects and do not represent a specific ordering of objects. It is understood that "first, second, third" may be interchanged in a specific order or sequence where permitted, so that the embodiments of this application described herein can be implemented in an order other than that illustrated or described herein.

[0023] In the embodiments of this application, the terms "module" or "unit" refer to a computer program or part of a computer program that has a predetermined function and works with other related parts to achieve a predetermined goal, and can be implemented wholly or partially using software, hardware (such as processing circuitry or memory), or a combination thereof. Similarly, a processor (or multiple processors or memory) can be used to implement one or more modules or units. Furthermore, each module or unit can be part of an overall module or unit that includes the functionality of that module or unit.

[0024] Unless otherwise defined, all technical and scientific terms used in the embodiments of this application have the same meaning as commonly understood by one of ordinary skill in the art. The terminology used in the embodiments of this application is for the purpose of describing the embodiments of this application only and is not intended to limit this application.

[0025] In the implementation of this application, the collection and processing of relevant data should strictly comply with the requirements of relevant laws and regulations, obtain the informed consent or separate consent of the personal information subject, and carry out subsequent data use and processing within the scope of laws and regulations and the authorization of the personal information subject.

[0026] Figure 1 This is a schematic diagram of the structure of a lithium battery and lead-acid battery shared system provided in the embodiments of this application. The following will be combined with... Figure 1 The system shown is described as follows: Figure 1 As shown, the system includes: UPS10, lead-acid battery pack 20 and multiple lithium battery units 30; lead-acid battery pack 20 connects UPS10 and multiple lithium battery units 30; lead-acid battery pack 20 is used to provide backup power to UPS10; The lithium battery unit 30 includes a lithium battery pack 302 and a DC-DC conversion circuit 301. The DC-DC conversion circuit 301 is used to convert the voltage of the electrical energy output from the lithium battery pack 302 so that the lithium battery unit 30 and the lead-acid battery pack 20 can be connected in parallel with the same discharge voltage to provide backup power for the UPS 10.

[0027] In practical applications, refer to Figure 2 As shown, the lead-acid battery pack 20 can be composed of multiple 12V lead-acid batteries connected in series. The nominal voltage of the lead-acid battery pack 20 is 12V×n (n is the number of batteries). The lead-acid battery pack 20 serves as the main backup power source during normal operation. When the lead-acid battery pack 20 is in the late stage of discharge or has insufficient capacity, the lithium battery unit 30 participates in power supply to extend the overall backup power time.

[0028] The lithium battery pack 302 is an energy storage module composed of multiple lithium battery cells, which has advantages such as high energy density, long cycle life, and small size. The voltage of the lithium battery pack 302 is usually lower than the nominal voltage of the lead-acid battery pack 20. Because the voltages of the lithium battery pack 302 and the lead-acid battery pack 20 are inconsistent, the two battery packs cannot be directly connected in parallel.

[0029] A DC-DC converter circuit is an electronic circuit that converts an input DC voltage into another output DC voltage, and is widely used in power management systems. The function of the DC-DC converter circuit is to boost the output voltage of the lithium battery pack 302 to the same voltage value as the lead-acid battery pack 20. The DC-DC converter circuit enables the lithium battery pack 302 and the lead-acid battery pack 20 to operate in parallel. The DC-DC converter circuit controls the output voltage and current by adjusting the duty cycle or switching frequency, thereby achieving precise voltage matching and current limiting control.

[0030] By setting the boost voltage of the lithium battery unit 30 to the nominal voltage of the lead-acid battery pack 20 (e.g., 12V×n), the lithium battery unit 30 can be kept in a dormant state during the initial discharge phase. As the voltage of the lead-acid battery pack 20 gradually decreases, the lithium battery unit 30 begins to participate in the discharge, eventually sharing the load with the lead-acid battery pack 20. Simultaneously, current limiting control of the DC-DC conversion circuit prevents excessive current from impacting the system, improving the overall stability and safety of the power supply.

[0031] During the initial discharge process, the lead-acid battery pack 20 discharges primarily, while the lithium battery cell 30 remains in a fully charged dormant state. As the voltage of the lead-acid battery pack 20 decreases, the lithium battery cell 30 begins to participate in the discharge until the lithium battery cell 30 reaches undervoltage protection, at which point the lead-acid battery pack 20 discharges independently. During the discharge phase, the lead-acid battery pack 20 initially bears the entire load. The float charge voltage of the lead-acid battery pack 20 can be set to 13.5V×n, which is higher than the boost voltage of the lithium battery cell 30.

[0032] Therefore, the lead-acid battery pack 20 discharges first, while the lithium battery unit 30 remains in standby mode. As the discharge time increases, the voltage of the lead-acid battery pack 20 gradually decreases. When it approaches the boost voltage of the lithium battery unit 30, the lithium battery unit 30 begins to discharge, gradually sharing the load. The undervoltage protection of the lithium battery unit 30 means that when the voltage of the lithium battery unit 30 drops to a set threshold, the system automatically cuts off the power supply to prevent over-discharge of the lithium battery unit 30, thereby extending its service life and preventing damage to related equipment. When the voltage of the lithium battery unit 30 drops to the undervoltage protection setting value, the system controls the DC-DC conversion circuit to enter a shutdown state. In this state, the UPS draws power from the lead-acid battery pack 20 to continue operating until the voltage of the lead-acid battery pack 20 also drops to the undervoltage protection setting value.

[0033] This coordinated discharge method improves the overall backup power time of the system and effectively extends the service life of the lead-acid battery pack 20. At the same time, due to the introduction of the lithium battery cell 30, the depth of discharge experienced by the lead-acid battery pack 20 is significantly reduced, thereby further improving the cycle life of the lead-acid battery pack 20.

[0034] As can be seen from the above, the lithium battery and lead-acid battery shared system provided in this application provides power by connecting multiple lithium battery units 30 in parallel with the lead-acid battery pack 20, and using a DC-DC conversion circuit to achieve voltage matching and current control, so that the lithium battery units 30 and the lead-acid battery pack 20 can work together, improving the overall power supply stability and reliability, and extending the service life of the lead-acid battery pack 20.

[0035] In some embodiments of this application, the lithium battery unit 30 includes a controller for setting the boost voltage value of the lithium battery unit 30 according to the nominal voltage value of the lead-acid battery pack 20, so that the lithium battery unit 30 and the lead-acid battery pack 20 are connected in parallel with the same discharge voltage to provide backup power for the UPS 10.

[0036] In practical applications, each DC-DC conversion circuit 301 includes a controller (not shown in the figure). The controller calculates the required boost voltage for the DC-DC conversion circuit 301 within the corresponding lithium battery cell 30 by real-time monitoring of the nominal voltage value (e.g., 12Vn) of the lead-acid battery pack 20, and controls the duty cycle of the switching devices (e.g., MOSFETs) to achieve voltage matching and current limiting protection. This ensures that the lithium battery cell 30 only participates in discharging at the appropriate time and avoids the risk of overload or short circuit.

[0037] The nominal voltage refers to the average voltage value of a battery under standard operating conditions. For example, the nominal voltage of a single lead-acid battery is 12V, and when n lead-acid batteries are connected in series, the total nominal voltage is 12Vn. The controller sets the boost target of the lithium battery unit 30 based on the nominal voltage, so that the lithium battery unit 30 has the same voltage level when connected in parallel with the lead-acid battery pack 20, thereby achieving seamless switching and coordinated power supply. The lithium battery unit 30 can be smoothly connected after the voltage of the lead-acid battery pack 20 drops to a similar level, gradually taking on more current, and finally completing the transition before the undervoltage protection of the lead-acid battery pack 20. At the same time, the controller can limit the maximum discharge current of the lithium battery unit 30 to prevent the lithium battery unit 30 from being damaged due to overload, thereby extending the life of the lithium battery unit 30 and improving the safety of the system.

[0038] Furthermore, since the lithium battery unit 30 has independent control capabilities, even if the lead-acid battery pack 20 fails, the DC-DC conversion circuit can still maintain system operation without affecting the overall system operation, thus improving system redundancy and fault tolerance. The controller, DC-DC conversion circuit, and lead-acid battery pack 20 work together to achieve parallel power supply between the lithium battery unit 30 and the lead-acid battery pack 20. By setting the controller to dynamically adjust the boost voltage of the lithium battery unit 30 according to the nominal voltage of the lead-acid battery pack 20, voltage matching and parallel power supply between the lithium battery unit 30 and the lead-acid battery pack 20 can be achieved. The controller ensures that the lithium battery unit 30 and the lead-acid battery pack 20 work together during discharge, enabling the UPS system to effectively cope with sudden power outages and ensuring the normal operation of critical equipment.

[0039] In some embodiments of this application, the controller is used to connect the lithium battery unit 30 and the lead-acid battery pack 20 in parallel when the discharge voltage of the lead-acid battery pack 20 reaches the boost voltage value, so as to provide backup power for the UPS 10.

[0040] In practical applications, the controller continuously monitors the discharge voltage of the lead-acid battery pack 20 and compares it with a preset boost voltage value. When the discharge voltage of the lead-acid battery pack 20 equals the preset boost voltage value, the controller connects the lithium battery unit 30 to the system for parallel power supply. Furthermore, since the float charge voltage of the lead-acid battery pack 20 is higher than the boost voltage of the lithium battery unit 30, in the initial stage of system operation, the load is mainly powered by the lead-acid battery pack 20, while the lithium battery unit 30 has completed charging and entered a dormant state. As the discharge process progresses, the voltage of the lead-acid battery pack 20 gradually decreases. When the voltage of the lead-acid battery pack 20 falls below the boost voltage of the lithium battery unit 30, the lithium battery unit 30 begins to discharge externally and gradually shares more of the load. Finally, when the voltage of the lithium battery unit 30 drops to the undervoltage protection threshold, the control module shuts down the DC-DC converter circuit until the lead-acid battery pack 20 also reaches the undervoltage protection level.

[0041] By adopting a technical solution that combines lead-acid battery pack 20 with lithium battery unit 30, the system achieves complementary advantages between the two. Lead-acid battery pack 20 serves as the main power source, providing large-capacity energy storage, while lithium battery unit 30 acts as an auxiliary power source, providing stable support during critical periods.

[0042] In some embodiments of this application, after the lithium battery unit 30 and the lead-acid battery pack 20 are connected in parallel, a controller is used to control the lithium battery unit 30 to discharge, and during the discharge process of the lithium battery unit 30, the controller controls the duty cycle or switching frequency of the DC-DC conversion circuit 301 to limit the discharge current of the lead-acid battery pack 20.

[0043] In practical applications, when the discharge voltage of the lead-acid battery pack 20 gradually decreases to near the boost voltage of the lithium battery cell 30, the controller initiates the discharge process of the lithium battery cell 30. At this time, to prevent the lead-acid battery pack 20 from aging prematurely due to overload, the controller dynamically adjusts the duty cycle or switching frequency of the DC-DC conversion circuit, thereby limiting the discharge current of the lead-acid battery pack 20. For example, the controller can gradually reduce the duty cycle, allowing the lithium battery cell 30 to bear more load while reducing the discharge pressure on the lead-acid battery pack 20. By rationally controlling the discharge ratio of the lithium battery cell 30 and the lead-acid battery pack 20, the system can extend the service life of the lead-acid battery pack 20 and improve overall energy efficiency while ensuring continuous power supply.

[0044] The controller adjusts the duty cycle or switching frequency of the DC-DC conversion circuit to limit the discharge current of the lead-acid battery pack 20. This method effectively protects the lead-acid battery pack 20 from overload damage, thereby extending its service life and improving the overall operating efficiency and stability of the UPS system.

[0045] In some embodiments of this application, the controller is configured to shut down the DC-DC conversion circuit 301 when the discharge voltage of the lithium battery cell 30 reaches a first undervoltage protection value.

[0046] In practical applications, when the discharge voltage of the lithium battery cell 30 drops to the set first undervoltage protection value, it indicates that the energy of the lithium battery cell 30 is about to be exhausted, and continued discharge may cause irreversible damage to the lithium battery cell 30. When the discharge voltage of the lithium battery cell 30 drops to the set first undervoltage protection value, the controller detects that the discharge voltage of the lithium battery cell 30 has reached the first undervoltage protection value and triggers the corresponding voltage threshold. The controller then issues a command to shut down the DC-DC conversion circuit, thereby cutting off the discharge path of the lithium battery cell 30, effectively preventing damage to the lithium battery cell 30 due to over-discharge, extending the service life of the lithium battery cell 30, and ensuring the safety of the entire system operation. Timely shutdown of the DC-DC conversion circuit ensures that the lead-acid battery pack 20 can independently complete the discharge task in subsequent stages, thus maintaining the continuity of power supply to the system. The first undervoltage protection value can be 10.5V×n.

[0047] In this embodiment, when the voltage of the lithium battery cell 30 drops to the undervoltage protection value, the control system shuts down the DC-DC conversion circuit to protect the lithium battery cell 30. This method avoids performance degradation of the lithium battery cell 30 due to over-discharge, thereby improving the reliability and stability of the entire energy storage system.

[0048] In some embodiments of this application, the controller is used to control the lead-acid battery to discharge after the DC-DC conversion circuit 301 is turned off, until the discharge voltage of the lead-acid battery reaches the second undervoltage protection value.

[0049] In practical applications, when the discharge voltage of the lithium-ion battery drops to the set first undervoltage protection value, the controller triggers a protection mechanism to cut off the DC-DC conversion circuit, preventing further discharge of the lithium-ion battery and excessive wear. At this time, the system switches to the lead-acid battery for continued power supply. The controller monitors the voltage state of the lead-acid battery and continuously controls the load output during the discharge process to ensure that the lead-acid battery operates according to the preset safety threshold until the discharge voltage of the lead-acid battery drops to the second undervoltage protection value.

[0050] The above process effectively prevents lead-acid batteries from over-discharging, extends their lifespan, and ensures the stability and safety of the entire system. The controller can be configured with a reasonable undervoltage protection point to prevent damage to the lead-acid batteries. The second undervoltage protection value for the lead-acid battery is typically set based on its rated capacity and the application environment. For example, for a 12V lead-acid battery pack 20, the second undervoltage protection value might be set to 10.5Vn (where n is the number of batteries connected in series). Once the discharge voltage of the lead-acid battery falls below the second undervoltage protection value, the controller stops discharging to prevent the battery from failing or having its lifespan shortened due to over-discharge. By having the controller take over the discharge management of the lead-acid battery after the DC-DC converter circuit is turned off, it is possible to ensure a smooth transition to lead-acid battery power supply mode after the lithium-ion battery stops operating, thus guaranteeing the continuity of power supply. This measure of having the controller take over the discharge management of the lead-acid battery after the DC-DC converter circuit is turned off effectively prevents over-discharge of the lithium-ion battery and avoids performance degradation of the lead-acid battery due to prolonged deep discharge. This maintains the overall energy efficiency and reliability of the system, thereby improving the overall lifespan and operational stability of the hybrid battery system.

[0051] By configuring the discharge sequence described above—lead-acid battery discharging first, lithium battery discharging together, and then each discharging to undervoltage protection—the configuration becomes more flexible. For example, it can better address scenarios where the backup power time is limited and only needed to supplement aging lead-acid batteries. The power of the lithium battery can be configured to be lower than that of the UPS or lead-acid battery, and the lithium battery discharge can be configured in the middle stage, allowing it to discharge together with the lead-acid battery. Furthermore, to ensure that the larger-capacity lead-acid battery is fully charged on each charge for longer backup power, the full-charge voltage of the lead-acid battery can be configured to be higher than that of the lithium battery, while the target boost voltage is the nominal voltage of the lead-acid battery. This allows the lead-acid battery to discharge first while ensuring it is fully charged.

[0052] In some embodiments of this application, a controller is used to receive current commands sent by the UPS10; the current commands are used to control the discharge current of each lithium battery cell 30 during the discharge process.

[0053] In practical applications, a current command is a control signal issued by the UPS to specify the exact current value that the lithium battery cell 30 should output during discharge. The current command is typically calculated based on current load demand, remaining battery capacity, and other system parameters, and is dynamically adjustable. By receiving and responding to current commands, the controller can achieve independent control of each lithium battery cell 30, thereby improving the overall system's response speed and reliability.

[0054] When the UPS detects an increase in load current, it sends a higher current command to the controller. The controller adjusts the operating parameters of the DC-DC converter based on the received current command, and controls the lithium battery unit 30 to release more current to meet the load demand. Conversely, when the load decreases, the controller reduces the discharge current of the lithium battery unit 30 to prevent over-discharge and damage to the lithium battery unit 30.

[0055] Furthermore, since each lithium battery cell 30 is equipped with an independent DC-DC converter, the controller can perform differentiated control on each lithium battery cell 30 according to the current command, thereby achieving current sharing and fault isolation. For example, when a lithium battery cell 30 fails, the controller can automatically remove the failed lithium battery cell 30 from the system and redistribute the current to the remaining unfailed lithium battery cells 30, ensuring that the remaining unfailed lithium battery cells 30 can still operate normally.

[0056] The controller receives the current command sent by the UPS and controls the discharge current of each lithium battery cell 30 according to the current command. The controller thus achieves precise control of the discharge process of the lithium battery pack, thereby avoiding the problem of reduced life of lithium battery cells 30 due to current imbalance, improving the stability and safety of the UPS system, and thus extending the backup power supply time of the UPS system and enhancing the reliability of the UPS system.

[0057] In some embodiments of this application, the controller is used to adjust the discharge current of the second lithium battery unit 30 during the discharge process based on a current command when the first lithium battery unit 30 fails; the first lithium battery unit 30 is any one of a plurality of lithium battery units 30; the second lithium battery unit 30 is any one of a plurality of lithium battery units 30; the first lithium battery unit 30 and the lithium battery unit 30 are different.

[0058] In practical applications, when the first lithium battery unit 30 malfunctions, the controller can automatically identify the fault state of the first lithium battery unit 30 and dynamically adjust the second lithium battery unit 30 according to a pre-set current command. This allows the controller to compensate for the output capacity of the first lithium battery unit 30, thereby maintaining the stable discharge performance of the entire battery pack. The dynamic adjustment of the second lithium battery unit 30 by the controller may include increasing the discharge current of the second lithium battery unit 30, so that the controller prompts the second lithium battery unit 30 to share some of the load originally borne by the first lithium battery unit 30.

[0059] The controller monitors the operating status of each lithium battery cell 30 in real time. If any lithium battery cell 30 is detected to be abnormal or malfunctioning, the fault handling mechanism is immediately activated. At this time, the controller reallocates current commands, allowing other normally functioning second lithium battery cells 30 to replace the function of the first lithium battery cell 30, ensuring that the overall system's continuous power supply capability does not decrease. This not only improves the system's fault tolerance but also avoids the risk of the entire lithium battery pack shutting down due to the failure of a single first lithium battery cell 30.

[0060] For example, in a UPS system comprising multiple series-connected lithium battery cells 30, if one lithium battery cell 30 fails due to an internal short circuit, overheating, or other reasons, the controller will automatically isolate the first lithium battery cell 30 and recalculate the current distribution scheme for the remaining lithium battery cells 30. During this process, the controller can adjust the duty cycle of the DC-DC converter to change the discharge current of each normal lithium battery cell 30, allowing the normal lithium battery cells 30 to share a higher load, thereby maintaining the overall output power of the system. Furthermore, since each DC-DC converter has a communication interface, the controller can also implement current sharing control and current redistribution functions. When one lithium battery cell 30 exits operation, the controller will evenly redistribute the current originally allocated to the first lithium battery cell 30 to the other normally operating lithium battery cells 30, ensuring that the entire system still maintains good load balance and efficient operation. In this embodiment, the controller dynamically adjusts the discharge current of the second lithium battery unit 30 when the first lithium battery unit 30 fails. The controller can effectively improve the reliability and fault tolerance of the lithium battery system, so that the lithium battery system can maintain continuous power supply under the condition of partial component failure. Furthermore, the controller can extend the service life of the lithium battery system and ensure the stability of power supply to critical equipment.

[0061] In some embodiments of this application, a controller is used to control the UPS10 to precharge the lead-acid battery pack 20 until the charging voltage of the lead-acid battery pack 20 reaches the turn-on voltage value. After the charging voltage of the lead-acid battery pack 20 reaches the turn-on voltage value, the UPS10 controls the lithium battery pack and the lead-acid battery pack 20 to charge simultaneously. During the charging process of the lithium battery pack, the duty cycle or switching frequency of the DC-DC conversion circuit 301 is controlled to limit the charging current of the lithium battery pack until the charging voltage of the lithium battery pack reaches the turn-on voltage value. Once the lithium battery pack's charging voltage reaches the activation voltage, the UPS10 is controlled to continue charging the lead-acid battery pack 20 until the lead-acid battery pack 20's charging voltage reaches the float charging voltage.

[0062] In practical applications, the turn-on voltage is typically higher than the discharge termination voltage of the lead-acid battery pack 20. For example, in a single 12V lead-acid battery pack 20, the turn-on voltage can be between 12.8V and 13.0V. The turn-on voltage is set to ensure that the internal plates of the lead-acid battery pack 20 have recovered to a level where they can safely accept charging, thus preventing premature charging of the lead-acid battery pack 20 and resulting in plate sulfation or electrolyte imbalance.

[0063] By raising the charging voltage of the lead-acid battery pack 20 to the start-up voltage value through the controller, the controller can effectively determine whether the lead-acid battery pack 20 has the conditions to continue charging, thereby ensuring the safety and efficiency of charging the lead-acid battery pack 20 and the lithium battery unit 30 simultaneously.

[0064] By setting appropriate pre-charge conditions, it can be ensured that the lead-acid battery pack 20 has sufficient charge capacity before entering the normal charging phase, thereby improving the overall reliability of the UPS system. By adopting an optimized charging management strategy, capacity loss due to undercharging of the lead-acid battery pack 20 can be reduced, thereby extending the service life of the lead-acid battery pack 20 and improving the overall system energy utilization rate.

[0065] The float charge voltage refers to the lower voltage continuously applied to the lead-acid battery pack 20 after it is fully charged, in order to maintain its fully charged state. For a battery pack consisting of multiple 12V lead-acid battery packs 20 connected in series, the float charge voltage can be 13.5V × n (where n is the number of batteries). The purpose of the float charge voltage is to prevent the lead-acid battery pack 20 from self-discharge and to avoid damage caused by overcharging, such as plate corrosion or electrolyte evaporation. When the charging voltage of the lead-acid battery pack 20 reaches the float charge voltage, it indicates that the lead-acid battery pack 20 has completed the main charging stage and entered the float charging stage. At this time, the UPS will continue to supply power with the float charge voltage to maintain the fully charged state of the lead-acid battery pack 20, while stopping further high-current charging of the lead-acid battery pack 20. Using an overcharge protection mechanism ensures that the lead-acid battery pack 20 will not be overcharged after it is fully charged, thereby extending the service life of the lead-acid battery pack 20 and ensuring the stability and safety of the UPS system during long-term operation.

[0066] By adjusting the turn-on voltage of the lead-acid battery pack 20 and using a DC-DC converter circuit to implement current-limited charging of the lithium battery unit 30, the charging state of the lead-acid battery pack 20 is maintained even after it reaches the float charge voltage. This achieves coordinated charging management between the lead-acid battery pack 20 and the lithium battery unit 30, thereby improving the overall efficiency of the UPS system and extending battery life. First, the lead-acid battery pack 20 is pre-charged to reach its turn-on voltage, ensuring it has the ability to accept normal charging. Then, the lithium battery unit 30 is current-limited charged through the DC-DC converter circuit, gradually reaching the same voltage level as the lead-acid battery pack 20 to ensure synchronous operation. Finally, when the lead-acid battery pack 20 reaches the float charge voltage, it switches to float charging mode to maintain its full charge state without overcharging. This process ensures the compatibility, safety, and efficient operation of the two different types of batteries in the UPS system.

[0067] A method for using both lithium batteries and lead-acid batteries, applied to the aforementioned system using both lithium batteries and lead-acid batteries; the method includes: Step S301: During the use of the lead-acid battery pack 20, the DC-DC conversion circuit 301 in each lithium battery unit 30 is controlled to perform voltage conversion on the electrical energy output by each lithium battery unit 30, so that the lithium battery unit 30 and the lead-acid battery pack 20 are connected in parallel with the same discharge voltage to provide backup power for the UPS10.

[0068] In practical applications, each lithium battery unit 30 is equipped with an independent DC-DC conversion circuit. The main function of the independent DC-DC conversion circuit is to boost or buck the output power of the lithium battery unit 30, ensuring that its output voltage matches the nominal voltage (e.g., 12Vn) of the lead-acid battery pack 20. By boosting or bucking the output power of the lithium battery unit 30 through the DC-DC conversion circuit, the lithium battery unit 30 and the lead-acid battery pack 20 can operate in parallel at the same voltage level, thus jointly powering the UPS. This ensures that the lead-acid battery pack 20 and the lithium battery unit 30 do not interfere with each other during discharge, and automatically distributes the current output according to the remaining charge and characteristics of each battery unit.

[0069] For example, in the initial stage, the lead-acid battery pack 20 undertakes the main discharge task due to its high voltage. As the discharge process proceeds, the lithium battery cell 30 gradually participates in power supply. Eventually, the lead-acid battery pack 20 and the lithium battery cell 30 work together until the lithium battery cell 30 triggers the undervoltage protection mechanism. Current limiting control can prevent the lithium battery cell 30 from overload discharge, thereby avoiding battery performance degradation or damage caused by high current discharge.

[0070] When the lead-acid battery pack 20 begins to discharge, it will discharge preferentially because its float charge voltage is higher than the boosted voltage of the lithium battery unit 30. At this time, the lithium battery unit 30 is fully charged but not discharged, serving only as a backup power source. As the discharge time increases, the voltage of the lead-acid battery pack 20 gradually decreases. When the voltage of the lead-acid battery pack 20 approaches the boosted voltage of the lithium battery unit 30, the lithium battery unit 30 begins to participate in the discharge. As the discharge continues, the discharge current of the lithium battery unit 30 gradually increases, eventually entering a current-limiting state, and it shares power supply with the lead-acid battery pack 20 for the UPS until the undervoltage protection of the lithium battery unit 30 is activated. After the undervoltage protection of the lithium battery unit 30 is activated, the lead-acid battery pack 20 independently completes the remaining discharge process. The lithium battery unit 30 not only replenishes energy when the performance of the lead-acid battery pack 20 degrades, but also effectively extends its service life. Furthermore, since each lithium battery unit 30 is equipped with an independent DC-DC conversion circuit, even if one lithium battery unit 30 fails, it will not affect the normal operation of the entire system. The various DC-DC conversion circuits can also communicate with each other to achieve current sharing control and fault compensation, thereby improving the reliability and adaptability of the system.

[0071] During the use of the lead-acid battery pack 20, the DC-DC conversion circuit in each lithium battery unit 30 is controlled to convert the electrical energy into voltage, so that the lithium battery unit 30 and the lead-acid battery pack 20 operate in parallel with the same voltage. This achieves coordinated discharge between the lithium battery unit 30 and the lead-acid battery pack 20, thereby improving the overall power supply capacity and system reliability, extending the life of the lead-acid battery pack 20, and ensuring the continuous and stable operation of the UPS.

[0072] In a feasible scenario, the method for sharing lithium batteries and lead-acid batteries according to the embodiments of this application can be implemented in the following way: 1. Set the boost voltage of the lithium battery pack to the nominal voltage of the lead-acid battery, which is 12V multiplied by the number of batteries connected in series, n (denoted as 12n). During the process of setting the boost voltage of the lithium battery pack to the nominal voltage of the lead-acid battery, the lithium battery output is current-limited through a DC-DC converter to ensure the safe and stable operation of the system.

[0073] 2. Once both sets of batteries are fully charged, the control system begins the discharge operation. In the initial stage, the lead-acid battery discharges, while the lithium battery remains fully charged and enters a dormant mode.

[0074] 3. As the lead-acid battery continues to discharge, its voltage gradually decreases to near the discharge voltage of the lithium battery, at which point the lithium battery begins to participate in the discharge process.

[0075] 4. As the discharge time is extended, the discharge current of the lithium battery gradually increases until it reaches the preset current limit value. At this time, the lithium battery and the lead-acid battery jointly supply power to the load, achieving coordinated discharge.

[0076] 5. When the lithium battery voltage drops to the undervoltage protection threshold, the DC-DC boost circuit automatically shuts down, and the system switches to independent discharge of the lead-acid battery until the lead-acid battery also reaches the undervoltage protection condition.

[0077] For the charging process, parameters can be set to ensure the safety and effectiveness of charging. For example, the charging voltage threshold of the lithium battery pack should be set to 13Vn, and the charging voltage of the lithium battery pack should be current-limited controlled by a DC-DC converter.

[0078] In the initial stage, the UPS power supply first charges the lead-acid battery. When the lead-acid battery voltage rises to 13Vn, the lithium battery also begins to be charged. The entire charging process will continue until both batteries are fully charged. During the charging process, the lithium battery enters a dormant state, and the lead-acid battery enters a float charge state.

[0079] In the embodiments of this application, the power of each DC-DC converter is 1 / m of the total power (m is the number of groups), and each group of DC-DC converters has independent control functions. In this way, even if one group fails, it will not affect the normal operation of the entire lithium battery system. It is only necessary to remove the faulty battery group.

[0080] This solution not only solves the problems of short lifespan and rapid performance degradation of lead-acid batteries, but also improves the energy utilization and operational reliability of the system by introducing lithium batteries and DC-DC converters.

[0081] Based on the foregoing embodiments, embodiments of this application provide an electronic device. Figure 4 This is a schematic diagram of a hardware structure of an electronic device according to an embodiment of the present invention. The electronic device 400 includes at least one processor 401 and a memory 402. Optionally, the electronic device 400 may further include at least one communication interface 403. The various components in the electronic device 400 are coupled together through a bus system 404. It can be understood that the bus system 404 is used to realize the connection and communication between these components. In addition to a data bus, the bus system 404 also includes a power bus, a control bus, and a status signal bus. However, for clarity, in... Figure 4 The general designated all buses as Bus System 404.

[0082] Based on the hardware implementation of the above program modules, the communication interface 403 is able to interact with other communication devices. The processor 401 is connected to the communication interface 403 to enable information interaction with other communication devices and to execute the methods provided by one or more of the above-mentioned technical solutions when running a computer program; Memory 402, the computer program is stored in memory 402.

[0083] Specifically, during the use of the lead-acid battery pack, the processor 401 controls the DC-DC conversion circuit in each lithium battery cell to convert the voltage of the electrical energy output by each lithium battery cell, so that the lithium battery cell and the lead-acid battery pack can be connected in parallel with the same discharge voltage to provide backup power for the uninterruptible power supply.

[0084] It is understood that memory 402 can be volatile memory or non-volatile memory, or both. Non-volatile memory can be read-only memory (ROM), programmable read-only memory (PROM), erasable programmable read-only memory (EPROM), electrically erasable programmable read-only memory (EEPROM), magnetic random access memory (FRAM), flash memory, magnetic surface memory, optical disc, or compact disc read-only memory (CD-ROM); magnetic surface memory can be disk storage or magnetic tape storage. Volatile memory can be random access memory (RAM), which is used as an external cache. By way of example, but not limitation, many forms of RAM are available, such as Static Random Access Memory (SRAM), Synchronous Static Random Access Memory (SSRAM), Dynamic Random Access Memory (DRAM), Synchronous Dynamic Random Access Memory (SDRAM), Double Data Rate Synchronous Dynamic Random Access Memory (DDRSDRAM), Enhanced Synchronous Dynamic Random Access Memory (ESDRAM), Sync Link Dynamic Random Access Memory (SLDRAM), and Direct Rambus Random Access Memory (DRRAM).The memory 402 described in this embodiment of the invention is intended to include, but is not limited to, these and any other suitable types of memory.

[0085] The memory 402 in this embodiment of the invention is used to store various types of data to support the operation of the electronic device 400. Examples of such data include any computer program for operation on the electronic device 400, and programs implementing the methods of this embodiment of the invention may be included in the memory 402.

[0086] The methods disclosed in the above embodiments of the present invention can be applied to processor 401, or implemented by processor 401. The processor may be an integrated circuit chip with signal processing capabilities. During implementation, each step of the above method can be completed by integrated logic circuits in the processor's hardware or by instructions in software form. The processor may be a general-purpose processor, a digital signal processor (DSP), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. The processor can implement or execute the methods, steps, and logic block diagrams disclosed in the embodiments of the present invention. A general-purpose processor may be a microprocessor or any conventional processor, etc. The steps of the methods disclosed in the embodiments of the present invention can be directly manifested as execution by a hardware decoding processor, or execution by a combination of hardware and software modules in the decoding processor. The software modules may be located in a storage medium, which is located in a memory. The processor reads information from the memory and, in conjunction with its hardware, completes the steps of the aforementioned method.

[0087] In an exemplary embodiment, the electronic device 400 may be implemented by one or more application-specific integrated circuits (ASICs), DSPs, programmable logic devices (PLDs), complex programmable logic devices (CPLDs), field-programmable gate arrays (FPGAs), general-purpose processors, controllers, microcontrollers (MCUs), microprocessors, or other electronic components to perform the methods described above.

[0088] This application provides a computer program product, which includes a computer program or computer-executable instructions stored in a computer-readable storage medium. A processor of an electronic device reads the computer-executable instructions from the computer-readable storage medium and executes the computer-executable instructions, causing the electronic device to perform the lithium battery and lead-acid battery sharing method described in this application embodiment.

[0089] This application provides a computer-readable storage medium storing computer-executable instructions or a computer program. When the computer-executable instructions or the computer program are executed by a processor, the processor will execute the lithium battery and lead-acid battery sharing method provided in this application. For example, ... Figure 3 The method shown is for using both lithium batteries and lead-acid batteries.

[0090] In some embodiments, the computer-readable storage medium may be a memory such as RAM, ROM, flash memory, magnetic surface memory, optical disk, or CD-ROM; or it may be a variety of devices including one or any combination of the above-mentioned memories.

[0091] In some embodiments, computer-executable instructions may take the form of programs, software, software modules, scripts, or code, written in any form of programming language (including compiled or interpreted languages, or declarative or procedural languages), and may be deployed in any form, including as stand-alone programs or as modules, components, subroutines, or other units suitable for use in a computing environment.

[0092] As an example, computer-executable instructions may, but do not necessarily, correspond to files in a file system. They may be stored as part of a file that holds other programs or data, for example, in one or more scripts in a Hyper Text Markup Language (HTML) document, in a single file dedicated to the program in question, or in multiple co-located files (e.g., files that store one or more modules, subroutines, or code sections).

[0093] As an example, computer-executable instructions can be deployed to execute on a single electronic device, or on multiple electronic devices located at one location, or on multiple electronic devices distributed across multiple locations and interconnected via a communication network.

[0094] In summary, the embodiments of this application connect multiple lithium battery cells and lead-acid battery packs in parallel for power supply, and use DC-DC conversion circuits to achieve voltage matching and current control, enabling the lithium battery cells and lead-acid battery packs to work together, improving the overall stability and reliability of power supply, and extending the service life of lead-acid battery packs.

[0095] The above are merely embodiments of this application and are not intended to limit the scope of protection of this application. Any modifications, equivalent substitutions, and improvements made within the spirit and scope of this application are included within the scope of protection of this application.

Claims

1. A system for sharing lithium batteries and lead-acid batteries, characterized in that, The system includes: An uninterruptible power supply (UPS), a lead-acid battery pack, and multiple lithium battery cells; the lead-acid battery pack is connected to the UPS and the multiple lithium battery cells; the lead-acid battery pack is used to provide backup power to the UPS. The lithium battery unit includes a lithium battery pack and a DC-DC conversion circuit; the DC-DC conversion circuit is used to convert the voltage of the electrical energy output by the lithium battery pack so that the lithium battery unit and the lead-acid battery pack can be connected in parallel with the same discharge voltage to provide backup power for the uninterruptible power supply.

2. The system according to claim 1, characterized in that, The lithium battery unit includes a controller for setting the boost voltage value of the DC-DC conversion circuit within the lithium battery unit according to the nominal voltage value of the lead-acid battery pack, so that the lithium battery unit and the lead-acid battery pack are connected in parallel with the same discharge voltage to provide backup power for the uninterruptible power supply.

3. The system according to claim 2, characterized in that, The controller is used to connect the lithium battery cell and the lead-acid battery pack in parallel when the discharge voltage of the lead-acid battery pack reaches the boost voltage value, so as to provide backup power for the uninterruptible power supply.

4. The system according to claim 3, characterized in that, After the lithium battery cell is connected in parallel with the lead-acid battery pack, the controller is used to control the lithium battery cell to discharge, and during the discharge process of the lithium battery cell, to control the duty cycle or switching frequency of the DC-DC conversion circuit to limit the discharge current of the lead-acid battery pack.

5. The system according to claim 4, characterized in that, The controller is used to shut down the DC-DC conversion circuit when the discharge voltage of the lithium battery cell reaches a first undervoltage protection value.

6. The system according to claim 5, characterized in that, The controller is used to control the lead-acid battery to discharge after the DC-DC conversion circuit is turned off, until the discharge voltage of the lead-acid battery reaches the second undervoltage protection value.

7. The system according to claim 2, characterized in that, The controller is used to receive current commands sent by the uninterruptible power supply; the current commands are used to control the discharge current of each lithium battery cell during the discharge process.

8. The system according to claim 7, characterized in that, The controller is configured to adjust the discharge current of the second lithium battery unit during the discharge process based on the current command when the first lithium battery unit fails; the first lithium battery unit is any one of the plurality of lithium battery units; the second lithium battery unit is any one of the plurality of lithium battery units; the first lithium battery unit and the lithium battery units are different.

9. The system according to claim 2, characterized in that, The controller is used to control the uninterruptible power supply to precharge the lead-acid battery pack until the charging voltage of the lead-acid battery pack reaches the turn-on voltage value. After the charging voltage of the lead-acid battery pack reaches the threshold voltage, the uninterruptible power supply is controlled to charge the lithium battery pack and the lead-acid battery pack simultaneously. During the charging process of the lithium battery pack, the duty cycle or switching frequency of the DC-DC conversion circuit is controlled to limit the charging current of the lithium battery pack until the charging voltage of the lithium battery pack reaches the threshold voltage. After the charging voltage of the lithium battery pack reaches the activation voltage value, the uninterruptible power supply is controlled to continue charging the lead-acid battery pack until the charging voltage of the lead-acid battery pack reaches the float charge voltage value.

10. A method for using both lithium batteries and lead-acid batteries, characterized in that, Applied to the lithium battery and lead-acid battery shared system according to any one of claims 1 to 9; the method includes: During the use of the lead-acid battery pack, the DC-DC conversion circuit in each lithium battery cell is controlled to convert the voltage of the electrical energy output by each lithium battery cell, so that the lithium battery cell and the lead-acid battery pack are connected in parallel with the same discharge voltage to provide backup power for the uninterruptible power supply.

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