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, a lithium battery pack and a direct current-direct current conversion circuit, the direct current-direct current conversion circuit is connected with the lead-acid battery pack and the lithium battery pack; the lead-acid battery pack is used for providing standby power for the uninterruptible power supply; 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 pack 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 introducing a DC-DC conversion circuit, voltage matching and parallel operation of the lithium battery pack and the lead-acid battery pack are achieved, thereby improving the overall power supply capacity of the system and extending the backup power time.

[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, a lithium battery pack, and a DC-DC converter circuit; the DC-DC converter circuit connects the lead-acid battery pack and the lithium battery pack; the lead-acid battery pack is used to provide backup power to the UPS; 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 pack 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 system also includes a controller connected to the DC-DC conversion circuit, which is used to set the boost voltage value of the lithium battery pack according to the nominal voltage value of the lead-acid battery pack, so that the lithium battery pack is connected in parallel with the lead-acid battery pack with the same discharge voltage after being regulated by the DC-DC conversion circuit, so as to provide backup power for the uninterruptible power supply.

[0007] In the above scheme, the controller is used to connect the lithium battery pack 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, before the lithium battery pack and the lead-acid battery pack are connected in parallel, the controller is used to control the lead-acid battery pack to pre-discharge so that the discharge voltage of the lead-acid battery pack reaches the boost voltage value.

[0009] In the above scheme, after the lithium battery pack and the lead-acid battery pack are connected in parallel, the controller is used to control the lithium battery pack to discharge, and during the discharge process of the lithium battery pack, 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.

[0010] In the above scheme, the controller is used to shut down the DC-DC conversion circuit when the discharge voltage of the lithium battery pack reaches the first undervoltage protection value.

[0011] 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.

[0012] In the above scheme, the controller is used to configure charging start parameters; the charging start parameters are used to indicate the start voltage value for simultaneous charging of the lithium battery pack and the lead-acid battery pack.

[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 opening 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 is controlled to convert the voltage of the electrical energy output by the lithium battery pack, so that the lithium battery pack 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.

[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 introducing a DC-DC conversion circuit, voltage matching and parallel operation of the lithium battery pack and the lead-acid battery pack are realized, thereby improving the overall power supply capacity of the system and extending the backup power time. 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: Uninterruptible power supply, lead-acid battery pack, lithium battery pack and DC-DC converter circuit; DC-DC converter circuit connects lead-acid battery pack and lithium battery pack; lead-acid battery pack is used to provide backup power to uninterruptible power supply; A DC-DC converter circuit is used to convert the voltage of the electrical energy output from the lithium battery pack so that the lithium battery pack 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.

[0027] In practical applications, refer to Figure 2As shown, the DC-DC converter circuit is used to adjust the output voltage of the lithium battery pack so that it matches the nominal voltage of the lead-acid battery pack, thereby enabling the lithium battery pack and the lead-acid battery pack to operate in parallel at the same voltage. For example, if the lead-acid battery pack consists of six 12V cells, the total voltage is 72V. In this case, the DC-DC converter circuit needs to adjust the voltage of the lithium battery pack to 72V so that the lithium battery pack and the lead-acid battery pack can be connected in parallel.

[0028] When the UPS switches to battery power mode, it prioritizes the use of lead-acid battery packs. As the lead-acid battery pack discharges, its voltage drops, at which point the lithium battery pack begins to contribute power through the DC-DC conversion circuit. The UPS system ensures a continuous and stable supply of power to the load.

[0029] The output voltage of the lithium battery pack is regulated by a DC-DC converter circuit to match the nominal voltage of the lead-acid battery pack. In this embodiment, the DC-DC converter circuit plays a crucial role in voltage matching. Furthermore, the DC-DC converter circuit also has a current-limiting function, limiting the maximum current output during the discharge of the lithium battery pack to prevent overload damage to the equipment.

[0030] The DC-DC converter circuit not only regulates voltage but also automatically switches to lead-acid battery power supply mode after the lithium battery pack undervoltage protection is activated. This automatic switch ensures stable system operation while preventing power outages due to depleted lithium batteries. After voltage matching, the lead-acid and lithium battery packs can be connected in parallel to power the UPS, improving overall power supply capacity. This increases the system's total backup time, effectively utilizes lead-acid battery resources, and reduces the cost of replacing all batteries.

[0031] The advantage of parallel connection is that when the lead-acid battery pack has a high voltage, it primarily powers the system. As the lead-acid battery pack discharges and its voltage gradually decreases, the lithium battery pack begins to contribute power until the set current limit is reached. At this point, both battery packs discharge together, ensuring continuous and stable operation of the UPS. This method effectively mitigates the performance degradation caused by lead-acid battery aging and extends the system's lifespan. To prevent overcurrent during lithium battery pack discharge, the DC-DC converter circuit can be configured with current-limiting parameters. These parameters represent the maximum allowable current during discharge. Once this maximum current is exceeded, the DC-DC converter circuit automatically limits the output current to protect the lithium battery pack from damage. The current-limiting parameters should be adjusted based on the actual capacity of the lithium battery pack and the UPS's load requirements to ensure safe operation. By setting appropriate current-limiting parameters, not only can the safe operation of the lithium battery pack be guaranteed, but the UPS can also maintain stable power supply even with load changes. Furthermore, dynamic adjustment of the current-limiting parameters can further optimize the system's response speed and operating efficiency.

[0032] When the voltage of the lithium battery pack falls below the preset undervoltage protection threshold, the DC-DC conversion circuit will automatically trigger the undervoltage protection mechanism, stopping the discharge operation of the lithium battery pack to prevent damage caused by over-discharge. The system allows setting the undervoltage protection threshold, which can be adjusted according to the lithium battery pack model and actual application scenario; for example, it can be set at approximately 90% of the battery pack's rated voltage. The undervoltage protection mechanism can promptly cut off the power supply path when the battery is about to run out of power, thus preventing the battery from having its lifespan shortened due to deep discharge. The undervoltage protection mechanism is of great significance for improving system reliability and extending battery life.

[0033] As can be seen from the above, the embodiments of this application achieve voltage matching and parallel operation of lithium battery pack and lead-acid battery pack by introducing a DC-DC conversion circuit, thereby improving the overall power supply capacity of the system, extending the backup power time, and effectively utilizing the original lead-acid battery resources.

[0034] In some embodiments of this application, the system further includes a controller connected to a DC-DC conversion circuit, used to set the boost voltage value of the lithium battery pack according to the nominal voltage value of the lead-acid battery pack, so that the lithium battery pack is connected in parallel with the lead-acid battery pack with the same discharge voltage after being regulated by the DC-DC conversion circuit, so as to provide backup power for the uninterruptible power supply.

[0035] In practical applications, the controller (not shown in the diagram) can read the nominal voltage value of the lead-acid battery pack (e.g., 12Vn), and then set the target boost voltage of the lithium battery pack based on this value. This ensures that the output voltage of the lithium battery pack after passing through the DC-DC converter is equal to the nominal voltage of the lead-acid battery pack. The controller uses this method to control the lithium battery pack and lead-acid battery pack to operate in parallel, allowing both to provide a stable backup power supply to the UPS. This avoids the problem of not being able to directly connect in parallel due to voltage inconsistencies between the lithium and lead-acid battery packs.

[0036] The controller can also dynamically adjust the output current limiting parameters of the lithium battery pack based on the discharge state of the lead-acid battery pack, ensuring that the two battery packs can coordinate and cooperate during discharge, thus extending the overall system lifespan. For example, in the initial stage of discharge of the lead-acid battery pack, due to its higher voltage, the lead-acid battery pack primarily supplies power to the load. As the discharge time increases, when the voltage of the lead-acid battery pack drops to near the boosted voltage of the lithium battery pack, the controller gradually controls the lithium battery pack to participate in power supply. Eventually, the lead-acid battery pack and the lithium battery pack share the load until the lead-acid battery pack enters the undervoltage protection stage, at which point the controller switches to allowing only the lithium battery pack to continue supplying power.

[0037] By precisely controlling the boost voltage of the lithium battery pack through a controller, the problem of insufficient backup power time caused by the degradation of lead-acid battery packs can be effectively solved. Simultaneously, the efficiency and stability of the combined operation of the lithium and lead-acid battery packs can be improved. Introducing a controller for precise control of the boost voltage of the lithium battery pack, and enhancing the efficiency and stability of the combined operation of the lithium and lead-acid battery packs, can improve the reliability of the entire UPS system, thereby extending system lifespan and reducing maintenance costs and replacement frequency.

[0038] In some embodiments of this application, a controller is configured to connect the lithium battery pack 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.

[0039] In practical applications, when the discharge voltage of the lead-acid battery pack drops to the same level as the set boost voltage of the lithium battery pack, the controller automatically adjusts the output voltage of the lithium battery pack through a DC-DC converter circuit to match the current voltage of the lead-acid battery pack. The lead-acid and lithium battery packs are then connected in parallel to jointly power the uninterruptible power supply (UPS) system. This process ensures that two batteries with different chemical properties can work together at the same voltage level, thereby improving overall backup time and system stability.

[0040] The controller's internal logic determines the discharge state of the lead-acid battery pack and controls the switching frequency or duty cycle of the DC-DC converter according to preset conditions, enabling dynamic connection and disconnection of the lithium battery pack. This method avoids current conflicts caused by differences in battery types and improves system operating efficiency. The controller also has a current limiting function, which can limit the maximum discharge current of the lithium battery pack, prevent overload or short circuit risks, and ensure the safety and reliability of the entire system.

[0041] As can be seen from the above, the controller automatically connects the lithium battery pack in parallel when the discharge voltage of the lead-acid battery pack reaches the set value, thereby realizing the coordinated discharge of the lead-acid battery pack and the lithium battery pack, improving the overall backup power capacity of the uninterruptible power supply system (UPS), thus extending the equipment operating time, reducing the risk of power outages, and improving system reliability.

[0042] In some embodiments of this application, before the lithium battery pack and the lead-acid battery pack are connected in parallel, a controller is used to control the lead-acid battery pack to pre-discharge so that the discharge voltage of the lead-acid battery pack reaches the boost voltage value.

[0043] In practical applications, the controller's functions may include monitoring the discharge voltage of the lead-acid battery pack and triggering corresponding control actions based on preset conditions, such as controlling the lead-acid battery pack to pre-discharge. The controller collects real-time voltage data of the lead-acid battery pack and compares it with a set boost voltage value. When the conditions are met, it issues a control command to initiate the discharge operation of the lead-acid battery pack.

[0044] Pre-discharge of lead-acid battery packs refers to the process where, before connecting the lead-acid battery pack and lithium battery pack in parallel, the controller actively controls the lead-acid battery pack to release some energy, gradually reducing its discharge voltage to a boost voltage value consistent with the output voltage of the lithium battery pack. This process of actively controlling the release of energy by the lead-acid battery pack before parallel connection ensures that the two battery packs have the same voltage level when connected in parallel, avoiding current surges or energy losses due to excessive voltage differences.

[0045] Pre-discharge can be achieved by the controller controlling the load switch, allowing the lead-acid battery pack to supply power to a controllable load, thus consuming some power until the discharge voltage of the lead-acid battery pack stabilizes near the target value. Alternatively, the controller can receive a command to initiate discharge to its own load. Since the target boost voltage of the lithium battery pack is the nominal voltage of the lead-acid battery pack, the lead-acid battery pack will naturally discharge first. The boost voltage refers to the output voltage of the lithium battery pack after adjustment by the DC-DC converter. The boost voltage is set to match the nominal voltage of the lead-acid battery pack (e.g., 12Vn). The boost voltage determines whether the lithium battery pack and the lead-acid battery pack can be safely connected in parallel. Once the discharge voltage of the lead-acid battery pack reaches the boost voltage, the lead-acid battery pack can be connected in parallel with the lithium battery pack, and both will jointly power the UPS.

[0046] By pre-discharging the lead-acid battery pack before parallel connection, the voltage of the lead-acid battery pack can be matched to the boost voltage of the lithium battery pack. This ensures that the lead-acid and lithium battery packs can be successfully connected in parallel, avoiding problems such as reverse current flow, energy waste, or circuit damage caused by voltage mismatch. This operating method achieves higher system stability and extends the lifespan of both the lead-acid and lithium battery packs.

[0047] The controller automatically completes the preparation work before the lead-acid battery pack and lithium battery pack are connected in parallel. Specifically, the controller actively controls the lead-acid battery pack to release some energy. The whole process does not require manual intervention, thereby improving the system's intelligence level and operating efficiency.

[0048] As described above, this embodiment uses a controller to pre-discharge the lead-acid battery pack, ensuring its discharge voltage reaches the same boost voltage as the lithium battery pack. This allows for safe parallel connection of the lead-acid and lithium battery packs, providing a stable backup power supply for the UPS. In practice, the controller continuously monitors the discharge voltage of the lead-acid battery pack. When the discharge voltage exceeds the target boost voltage, the controller automatically triggers the discharge mechanism, controlling the lead-acid battery pack to release energy and gradually reduce its discharge voltage. Once the discharge voltage drops to the boost voltage, the controller allows the lithium battery pack to connect in parallel with the lead-acid battery pack to the UPS system, achieving seamless switching and stable power supply.

[0049] 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.

[0050] In some embodiments of this application, after the lithium battery pack and the lead-acid battery pack are connected in parallel, a controller is used to control the lithium battery pack to discharge, and during the discharge process of the lithium battery pack, the duty cycle or switching frequency of the DC-DC conversion circuit is controlled to limit the discharge current of the lead-acid battery pack.

[0051] In practical applications, duty cycle refers to the ratio of the on-time of the switching transistor within one cycle to the total cycle time, while switching frequency refers to the frequency at which switching actions occur. These two parameters together determine the output power and current characteristics of the DC-DC converter circuit. By controlling the duty cycle or switching frequency of the DC-DC converter circuit through a control system, the discharge current of the lead-acid battery pack can be effectively limited during the discharge of the lithium battery pack, preventing performance degradation or shortened lifespan due to over-discharge.

[0052] By controlling the duty cycle or switching frequency of the DC-DC conversion circuit, the lithium battery pack undertakes the main discharge task in parallel operation, thereby protecting the lead-acid battery pack and extending its service life.

[0053] As the voltage of the lead-acid battery pack gradually decreases to near the boost voltage of the lithium battery pack, the discharge ratio of the lithium battery pack is gradually increased. At this time, the DC-DC conversion circuit dynamically adjusts the duty cycle or switching frequency according to the controller command, so that the current output by the lithium battery pack meets the load requirements while avoiding damage to the lead-acid battery pack due to over-discharge.

[0054] Control strategies that manage the duty cycle or switching frequency of the DC-DC converter circuit can further improve the overall stability and efficiency of the system. Because supercapacitors have higher energy density and longer cycle life, a reasonable allocation of the discharge ratio between supercapacitors and lithium battery packs can maximize resource utilization efficiency while ensuring continuous power supply. This collaborative working mode is suitable for scenarios with high requirements for power stability and reliability, such as uninterruptible power supplies (UPS).

[0055] As can be seen from the above, by controlling the duty cycle or switching frequency of the DC-DC conversion circuit, the discharge current of the lead-acid battery pack can be effectively limited, which can prevent the lead-acid battery pack from deteriorating due to over-discharge, thereby extending the service life of the lead-acid battery pack and improving the reliability and economy of the uninterruptible power supply system.

[0056] In some embodiments of this application, the controller is configured to shut down the DC-DC conversion circuit when the discharge voltage of the lithium battery pack reaches a first undervoltage protection value.

[0057] In practical applications, when the discharge voltage of a lithium battery pack drops to a preset first undervoltage protection value, it indicates that the lithium battery pack is about to enter an unsustainable discharge state. In this situation, continuing to adjust the output through the DC-DC converter circuit may cause further damage to the lithium battery pack or prevent it from recharging normally. To prevent this, after the controller detects that the discharge voltage of the lithium battery pack has reached the voltage threshold corresponding to the first undervoltage protection value, the controller immediately shuts down the DC-DC converter circuit, thereby preventing permanent damage to the lithium battery pack from over-discharge. The first undervoltage protection value refers to a lower voltage limit set during the discharge process of the lithium battery pack. This lower voltage limit is usually set within the safe operating range of the lithium battery pack and is slightly higher than the minimum discharge cutoff voltage. For example, for a 3.7V single-cell lithium battery, the first undervoltage protection value can be set to 3.2V. When setting the first undervoltage protection value, factors such as the chemical characteristics of the lithium battery pack, load requirements, and system reliability need to be considered to ensure the continuity of system operation while protecting the battery.

[0058] Shutting down the DC-DC converter circuit means setting the drive signal of the DC-DC converter's switching transistor to a low level, causing the DC-DC converter to stop working and thus disconnecting the power transmission path between the lithium battery pack and the load. The shutdown operation can be a soft shutdown (gradually reducing output power) or a hard shutdown (direct disconnection), depending on the system design and the system's tolerance to load switching. In this way, the DC-DC converter circuit is shut down promptly when the lithium battery pack's discharge voltage drops to a safe critical point, avoiding problems such as capacity decay and increased internal resistance caused by over-discharge of the lithium battery pack. It also ensures the continuity of power supply to the system, as the lead-acid battery remains usable and can seamlessly take over the power supply task. This not only extends the lifespan of the lithium battery pack but also enhances the stability and safety of the entire hybrid power system.

[0059] By setting a reasonable first undervoltage protection value, when the discharge voltage of the lithium battery pack approaches the safety boundary, the controller triggers the protection mechanism, shuts down the DC-DC conversion circuit, and thus cuts off the output path of the lithium battery pack; finally, the lead-acid battery takes over the power supply, realizing a smooth transition and efficient operation of the hybrid power system.

[0060] In some embodiments of this application, 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.

[0061] In practical applications, when the DC-DC conversion circuit is shut down by the controller due to the lithium battery voltage dropping to the first undervoltage protection value, the system will switch to a mode powered only by the lead-acid battery. At this time, the controller continues to manage the discharge process of the lead-acid battery to ensure that it is not over-discharged, which could lead to damage or performance degradation.

[0062] The controller continuously monitors the output voltage of the lead-acid battery. When the battery voltage drops to a preset second undervoltage protection value, the controller triggers a protection mechanism to stop the battery's discharge process, thus protecting its safe operation. The second undervoltage protection value refers to the lowest permissible safe voltage threshold during discharge, typically set based on the battery's chemical characteristics and application requirements. For example, in a 12V lead-acid battery system, the second undervoltage protection value might be set to around 10.5V to prevent deep discharge, thereby avoiding irreversible capacity loss and shortened battery life.

[0063] The controller's role in the phase where it controls the lead-acid battery to discharge after the DC-DC converter circuit is shut down is not only to disconnect the load, but also to record the discharge status, determine whether a fault mode has been entered, and reactivate the power supply path after conditions recover. This phased power management approach, corresponding to the controller's role in controlling the lead-acid battery to discharge after the DC-DC converter circuit is shut down, effectively extends the lifespan of both types of batteries and improves the overall system reliability and energy efficiency.

[0064] After detecting the DC-DC converter circuit is shut down, the controller controls the lead-acid battery to discharge, stopping the discharge when the battery voltage drops to a preset second undervoltage protection value. Upon detecting lithium battery failure, the power management system automatically switches to lead-acid battery power while preventing over-discharge, thus achieving more stable and safer power management. This power management method, based on controller-controlled lead-acid battery discharge and undervoltage protection, ensures continuous operation of equipment in emergency situations, improving the fault tolerance and reliability of the power supply system and meeting the power supply requirements of high-availability applications.

[0065] In some embodiments of this application, a controller is used to configure charging start parameters; the charging start parameters are used to indicate the start voltage value for simultaneous charging of the lithium battery pack and the lead-acid battery pack.

[0066] In practical applications, the charging start parameter refers to a voltage threshold set when the system starts charging both the lithium-ion battery pack and the lead-acid battery pack simultaneously. When the charging voltage of the lead-acid battery pack reaches the charging start parameter, the controller will allow the lithium-ion battery pack to begin charging. Setting the charging start parameter ensures that the lithium-ion battery pack and the lead-acid battery pack can enter the charging process simultaneously at the appropriate time, thereby improving the system's energy utilization and operating efficiency.

[0067] For example, in a UPS (Uninterruptible Power Supply) system, the lead-acid battery pack is first charged to a set start-up voltage (e.g., 13nV). Upon detecting this start-up voltage, the controller simultaneously initiates the charging process for the lithium battery pack. This synchronized charging of the lithium battery pack upon detection of the start-up voltage avoids energy waste or system instability caused by charging the lithium battery pack too early or too late.

[0068] By setting reasonable charging start parameters in the control system, the lithium battery pack can be charged in a timely and effective manner while ensuring the safe charging and discharging of the lead-acid battery pack. This achieves the optimal state of coordinated operation between the lithium and lead-acid battery packs. Configuring these charging start parameters defines the starting voltage value for simultaneous charging of the lithium and lead-acid battery packs, allowing control over the timing of simultaneous charging. This optimizes charging efficiency and further enhances the overall energy management capabilities of the system.

[0069] In some embodiments of this application, a 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. Once the lead-acid battery pack reaches the activation voltage, the uninterruptible power supply (UPS) is controlled to charge both 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 converter circuit is controlled to limit the charging current of the lithium battery pack until the charging voltage of the lithium battery pack reaches the activation voltage. Once the lithium battery pack reaches the activation voltage, the uninterruptible power supply continues to charge the lead-acid battery pack until the lead-acid battery pack reaches the float charge voltage.

[0070] In practical applications, the controller can monitor the voltage changes of the lead-acid battery pack in real time and trigger the next operation when the voltage of the lead-acid battery pack reaches the set threshold voltage. The threshold voltage is a key parameter set by the controller, representing the voltage threshold at which the lead-acid battery pack begins to allow the lithium battery pack to join the charging process. When the voltage of the lead-acid battery pack reaches the threshold voltage, it means that the lead-acid battery pack has a certain energy storage capacity and can withstand the impact of parallel charging, thus preparing for the subsequent charging of the lithium battery pack.

[0071] The controller manages the initial charging of the lead-acid battery pack, ensuring its voltage reaches a safe level before introducing the lithium battery pack. This avoids risks such as overcurrent and overvoltage due to voltage mismatch, improving system charging efficiency and safety while extending battery life. Once the lead-acid battery pack reaches its charging threshold, the controller controls the UPS (Uninterruptible Power Supply) to charge both the lithium and lead-acid battery packs simultaneously. During lithium battery charging, the controller controls the duty cycle or switching frequency of the DC-DC converter circuit to limit the charging current until the lithium battery pack reaches its charging threshold. After the lead-acid battery pack reaches its threshold, the controller switches to the next stage, charging both the lead-acid and lithium battery packs simultaneously. In synchronous charging mode, the controller fully utilizes the UPS's power resources, thereby improving overall charging efficiency.

[0072] The DC-DC converter circuit is used to regulate the charging voltage and current of the lithium battery pack to ensure that the lithium battery pack is not damaged by excessively high charging rates. Higher switching frequencies can reduce filter size but increase switching losses; lower switching frequencies result in larger filter size but reduced switching losses. By controlling the duty cycle or switching frequency of the DC-DC converter circuit, the controller can dynamically adjust the charging current of the lithium battery pack, keeping it within a safe range. The purpose of controlling the duty cycle or switching frequency of the DC-DC converter circuit is to prevent thermal runaway or shortened lifespan of the lithium battery pack due to excessive current during the initial charging phase. Intelligent charging strategies allow lead-acid and lithium battery packs to work together, ensuring charging efficiency while avoiding damage to the lithium battery pack caused by current surges.

[0073] When the lithium battery pack's charging voltage reaches the activation voltage, the controller readjusts the UPS (Uninterruptible Power Supply) operating mode, shifting the focus back to the lead-acid battery pack's charging process. With the lithium battery pack reaching the activation voltage, it has entered a stable charging phase, while the lead-acid battery pack continues charging to reach a higher voltage level. The float charge voltage is the maintenance voltage of the lead-acid battery pack after it is fully charged, typically slightly higher than the normal charging voltage, used to compensate for power loss due to battery self-discharge. In this embodiment, the float charge voltage is set to 13.5Vn, where n represents the number of batteries connected in series. This float charge voltage effectively maintains the lead-acid battery pack at full charge while avoiding safety issues caused by overcharging.

[0074] The battery packs work in close coordination. The controller, as the core control unit, coordinates the operation of each component to ensure a smooth and orderly charging process. The UPS (Uninterruptible Power Supply), as the main charging power source, provides a stable current input to the lead-acid battery packs while simultaneously finely controlling the charging behavior of the lithium battery packs through a DC-DC conversion circuit. Due to their superior tolerance, the lead-acid battery packs complete the initial charging first, paving the way for the subsequent connection of the lithium battery packs. Finally, the lead-acid battery packs continue charging to their float charge voltage value; the system maintains the optimal performance state of the lead-acid battery packs through this operation.

[0075] By configuring a controller to pre-charge the lead-acid battery pack using the UPS, and then simultaneously charging both the lithium-ion and lead-acid battery packs, the UPS controls the duty cycle or switching frequency of the DC-DC converter circuit during lithium-ion battery pack charging to limit the charging current. Finally, the UPS continues charging the lead-acid battery pack to its float charge voltage. This charging control method ensures coordinated operation of the two battery packs during charging, balancing charging efficiency and safety, and ultimately improving the reliability and lifespan of the entire energy storage system.

[0076] 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, the DC-DC conversion circuit is controlled to convert the voltage of the electrical energy output by the lithium battery pack so that the lithium battery pack and the lead-acid battery pack are connected in parallel with the same discharge voltage to provide backup power for the uninterruptible power supply.

[0077] In practical applications, the float charge voltage of a lead-acid battery pack is typically 13.5V×n (where n represents the number of batteries connected in series), while the boost voltage of a lithium battery pack is set to 12V×n. The DC-DC converter circuit then boosts the lithium battery pack voltage to match that of the lead-acid battery pack. Because the initial voltage of the lead-acid battery pack is higher, it primarily supplies power to the load during the initial discharge phase. As both the lead-acid and lithium battery packs discharge, the lithium battery pack gradually participates in the power supply process until it triggers its undervoltage protection mechanism, at which point it stops discharging, and only the lead-acid battery pack continues to supply power to the load.

[0078] It can effectively extend the lifespan of lead-acid battery packs and still guarantee the backup power time of the UPS system after the performance of lead-acid battery packs degrades. By operating lithium battery packs in parallel with lead-acid battery packs, not only is the overall power supply stability of the system improved, but the replacement frequency and maintenance costs caused by the aging of lead-acid battery packs are also reduced.

[0079] The output voltage of the lithium battery pack is adjusted by controlling the DC-DC conversion circuit, so that the lithium battery pack and the lead-acid battery pack can operate in parallel with the same voltage.

[0080] As described above, the embodiments of this application can achieve coordinated discharge between lithium battery packs and lead-acid battery packs, thereby balancing the discharge characteristics of lithium battery packs and lead-acid battery packs at different stages of use. This improves the overall backup power capacity and reliability of the UPS system. Through the voltage regulation function of the DC-DC conversion circuit, the system enables the lithium battery pack and lead-acid battery pack to operate in parallel at the same voltage, thus achieving coordinated discharge of the two battery packs. In actual implementation, the lead-acid battery pack initially bears most of the load. As the discharge process progresses, the lithium battery pack gradually participates in power supply, forming a dynamically balanced power supply mechanism, extending the service life of the lead-acid battery pack, and reducing overall maintenance costs.

[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, the processor 401 is used to control the DC-DC conversion circuit to convert the voltage of the electrical energy output from the lithium battery pack during the use of the lead-acid battery pack, so that the lithium battery pack 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 achieve voltage matching and parallel operation of lithium battery pack and lead-acid battery pack by introducing a DC-DC conversion circuit, thereby improving the overall power supply capacity of the system and extending the backup power time.

[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, a lithium battery pack, and a DC-DC converter circuit; the DC-DC converter circuit connects the lead-acid battery pack and the lithium battery pack; the lead-acid battery pack is used to provide backup power to the UPS; 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 pack 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 system also includes a controller connected to the DC-DC conversion circuit, used to set the boost voltage of the lithium battery pack according to the nominal voltage of the lead-acid battery pack, so that the lithium battery pack, after being regulated by the DC-DC conversion circuit, is connected in parallel with the lead-acid battery pack at 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 configured to connect the lithium battery pack 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, Before the lithium battery pack and the lead-acid battery pack are connected in parallel, the controller is used to control the lead-acid battery pack to pre-discharge so that the discharge voltage of the lead-acid battery pack reaches the boost voltage value.

5. The system according to claim 3, characterized in that, After the lithium battery pack and the lead-acid battery pack are connected in parallel, the controller is used to control the lithium battery pack to discharge, and during the discharge process of the lithium battery pack, 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.

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

7. The system according to claim 6, 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.

8. The system according to claim 2, characterized in that, The controller is used to configure charging start parameters; the charging start parameters are used to indicate the start voltage value for simultaneous charging of the lithium battery pack and the lead-acid battery pack.

9. The system according to claim 8, 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 opening 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 is controlled to convert the voltage of the electrical energy output by the lithium battery pack, so that the lithium battery pack 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.

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