DCDC converter and control method thereof, and communication base station power supply system

Abstract

The invention provides a DCDC converter, a control method thereof and a communication base station power supply system. A busbar connecting end of the DCDC converter is connected with a DC busbar, and a battery connecting end of the DCDC converter is connected with a battery module; the DCDC converter is used for adjusting the duration that the current of the battery connecting end is greater than or equal to a first current threshold to a second duration when the duration that the current of the battery connecting end is less than a first current threshold is less than a first duration and the voltage of the battery connecting end is less than a first voltage threshold, or adjusting the duration that the current of the battery connecting end is greater than or equal to the first current threshold to a second duration, adjusting the duration that the voltage of the battery connection end is greater than or equal to the first voltage threshold to a third duration; and when the duration in which the current of the battery connecting end is less than the first current threshold is greater than or equal to the first duration, adjusting the duration in which the current of the battery connecting end is greater than or equal to the first current threshold to a fourth duration. The DCDC converter can prevent the battery module from entering the sleep mode in the process of controlling the battery module.

Description

Technical Field

[0001] This application relates to the field of power electronics technology, specifically to a DC-DC converter and its control method, and a power supply system for communication base stations. Background Technology

[0002] In a communication base station power supply system, the DC bus distributes DC power to various loads within the base station. The lithium batteries in this system act as energy storage, supplying power to the DC bus during power outages, thus ensuring a stable power supply for the communication base station. To enable intelligent control of the lithium batteries, a DC-to-DC converter (DCDC) is installed between the lithium batteries and the DC bus. This DCDC converter can control the lithium batteries to perform functions such as cyclic discharge, tiered backup power, and tiered charging.

[0003] Typically, lithium batteries have an internal Battery Management System (BMS) that manages the charging and discharging process according to the specifications set by the lithium battery manufacturer. However, during the process of the DC-DC converter controlling the lithium battery for cycle discharge, tiered backup power, or tiered charging, the BMS may trigger the lithium battery to enter a sleep mode based on the charging and discharging mode specified by the lithium battery manufacturer. In this situation, if a power outage occurs in the communication base station's power supply system, the voltage of the DC bus will drop because the lithium battery cannot supply power to the DC bus in sleep mode, leading to a load power failure. Therefore, how to prevent the lithium battery from entering a sleep mode when using a DC-DC converter for control is a technical problem that urgently needs to be solved by those skilled in the art. Summary of the Invention

[0004] This application provides a DC-DC converter and its control method, as well as a power supply system for a communication base station. The DC-DC converter can prevent the battery module from entering a sleep mode during the control process, ensuring the stability of the power supply to the communication base station and has strong applicability.

[0005] In a first aspect, this application provides a DC-DC converter, wherein the busbar connection terminal of the DC-DC converter is used to connect to the DC busbar of the power supply system of a communication base station, and the battery connection terminal of the DC-DC converter is used to connect to a battery module; the DC-DC converter is used to convert the DC power supplied by the battery module into voltage and supply it to the DC busbar, or to convert the DC power supplied by the DC busbar into voltage and supply it to the battery module for charging; the DC-DC converter is also used for:

[0006] When the duration for which the current at the battery connection terminal is less than the first current threshold is less than the first duration, and the voltage at the battery connection terminal is less than the first voltage threshold, the duration for which the current at the battery connection terminal is greater than or equal to the first current threshold is adjusted to the second duration, or the duration for which the voltage at the battery connection terminal is greater than or equal to the first voltage threshold is adjusted to the third duration.

[0007] When the duration for which the current at the battery connection terminal is less than the first current threshold is greater than or equal to the first duration, the duration for which the current at the battery connection terminal is greater than or equal to the first current threshold is adjusted to the fourth duration.

[0008] In this embodiment, the battery module may enter a sleep mode (i.e., the battery module stops charging and discharging) when idle to reduce power consumption. For example, the battery pack inside the battery module is connected to the battery module output terminal via a switching unit. When the switching unit is normally off, the battery module enters a sleep mode. However, the DC bus in the communication base station power supply system may require power from the battery module at any time, so it is necessary to prevent the battery module from entering a sleep mode. The triggering condition for the battery module to enter a sleep mode includes a continuously low charging and discharging current. The DC-DC converter can then promptly increase the charging and discharging current of the battery module when it detects that the current is continuously low, thus preventing the current from remaining continuously low and thus failing to meet the triggering condition for entering a sleep mode. Simultaneously, since the battery connection terminal is connected to the battery module, the DC-DC converter can determine whether the charging and discharging current of the battery module is continuously low by detecting the current at the battery connection terminal. In this embodiment, the charging and discharging current of the battery module is continuously low when the current at the battery connection terminal is less than a first current threshold for a duration greater than or equal to a first duration. At this point, the DC-DC converter actively adjusts the duration for which the current at the battery connection terminal is greater than or equal to the first current threshold to a fourth duration. This prevents the charging and discharging current of the battery module from remaining consistently low, thus preventing the battery module from entering a sleep mode. Furthermore, since there is no communication connection between the battery module and the DC-DC converter, their current detection may be asynchronous. Therefore, in this embodiment, the DC-DC converter combines voltage and current changes at the battery connection terminal to comprehensively determine whether to actively adjust the battery module's charging and discharging to ensure that the battery module does not enter a sleep mode. Specifically, when the duration for which the current at the battery connection terminal is less than the first current threshold is less than the first duration, and the voltage at the battery connection terminal is less than the first voltage threshold, the charging and discharging current of the battery module may already be relatively low. In this case, the DC-DC converter actively adjusts the duration for which the current at the battery connection terminal is greater than or equal to the first current threshold to a second duration, preventing the charging and discharging current of the battery module from remaining consistently low, thus preventing it from entering a sleep mode. Alternatively, the DC-DC converter actively adjusts the duration for which the voltage at the battery connection terminal is greater than or equal to a first voltage threshold to a third duration, so that the battery module determines that the DC-DC converter can provide charging voltage to charge the battery module, thus preventing the battery module from entering sleep mode. Therefore, in this embodiment, the DC-DC converter does not need to communicate with the battery module to effectively prevent the battery module from entering sleep mode, making it highly applicable. Furthermore, the DC-DC converter adjusts the duration of the increased current at the battery connection terminal to a second or fourth duration because if the duration of the increased current is too short, the battery module may not be able to detect the increased current.Therefore, by adjusting the duration of the current in the DC-DC converter to the second or fourth duration, the battery module can accurately detect the increase in current. This allows the battery module to effectively and accurately detect that the charging and discharging current is greater than the trigger condition for entering the sleep mode (i.e., the current is greater than the first current threshold), ensuring that the battery module will not enter the sleep mode and thus ensuring high reliability.

[0009] In one possible implementation, when the duration for which the current at the battery connection is less than a first current threshold is less than a first duration, and the voltage at the battery connection is less than a first voltage threshold, the DC-DC converter adjusts the current at the battery connection to be greater than or equal to the first current threshold, specifically including:

[0010] When the duration for which the current at the battery connection terminal is less than the first current threshold is less than the first duration, and the voltage at the battery connection terminal is less than the first voltage threshold, the DC-DC converter adjusts the voltage at the battery connection terminal and provides the DC power supplied by the DC bus to the battery module for charging, so as to adjust the current at the battery connection terminal to be greater than or equal to the first current threshold.

[0011] In this embodiment, when the battery module is not fully charged, the DC-DC converter converts the DC power supplied by the DC bus to voltage and provides it to the battery module, enabling the battery module to charge and generate a charging current. During this process, the DC-DC converter adjusts the voltage at the battery connection terminal, thereby regulating the charging current of the battery module. Since the charging current is the same as the current flowing through the battery connection terminal, the DC-DC converter can regulate the current at the battery connection terminal simply by adjusting the voltage at the connection terminal, making the principle simple. Furthermore, if the voltage at the battery connection terminal is lower than a first voltage threshold, the battery module may have insufficient charge. In this case, the DC-DC converter controls the charging of the battery module to regulate the current at the battery connection terminal, preventing over-discharge of the battery module.

[0012] In one possible implementation, when the duration for which the current at the battery connection terminal is less than a first current threshold is less than a first duration, and the voltage at the battery connection terminal is less than a first voltage threshold, the DC-DC converter adjusts the voltage at the battery connection terminal to be greater than or equal to the first voltage threshold, specifically including:

[0013] When the duration for which the current at the battery connection terminal is less than the first current threshold is less than the first duration, and the voltage at the battery connection terminal is less than the first voltage threshold, the DC-DC converter adjusts the voltage at the battery connection terminal and converts the DC power supplied by the DC bus to charge the battery module, thereby adjusting the voltage at the battery connection terminal to be greater than or equal to the first voltage threshold.

[0014] In this embodiment, when the battery module is fully charged, the DC-DC converter converts the DC power supplied by the DC bus and provides it to the battery module, preventing further charging. However, the DC-DC converter can still adjust the voltage at the battery connection terminal to increase the voltage, a simple principle. Furthermore, when the voltage at the battery connection terminal is lower than a first voltage threshold, the DC-DC converter converts the voltage supplied by the DC bus to adjust the voltage at the battery connection terminal to be greater than or equal to the first voltage threshold. This prevents the battery module from entering a sleep mode and reduces power loss in the battery module.

[0015] In one possible implementation, when the current at the battery connection terminal is less than a first current threshold for a duration greater than or equal to a first duration, the DC-DC converter adjusts the current at the battery connection terminal to be greater than or equal to the first current threshold, specifically including:

[0016] When the duration of the current at the battery connection terminal being less than the first current threshold is greater than or equal to the first duration, and the voltage at the battery connection terminal is less than the rated charging voltage of the battery module, while the voltage at the busbar connection terminal is greater than the target voltage of the DC busbar, the DC converter adjusts the voltage at the battery connection terminal and converts the DC power supplied by the DC busbar to charge the battery module, thereby adjusting the current at the battery connection terminal to be greater than or equal to the first current threshold.

[0017] In this embodiment, the voltage at the battery connection terminal is less than the rated charging voltage of the battery module, indicating that the battery module is not fully charged. The voltage at the busbar connection terminal is greater than the target voltage of the DC busbar, indicating that the DC busbar has excess power. At this time, the DC-DC converter converts the DC power supplied by the DC busbar and provides it to the battery module for charging. This effectively adjusts the DC busbar voltage to the target voltage and enables charging of the lithium battery module, making it highly versatile. Furthermore, during the voltage conversion process of the DC power supplied by the DC busbar, the DC-DC converter can adjust the charging current of the battery module by adjusting the voltage at the battery connection terminal, thereby adjusting the current at the battery connection terminal. The principle is simple.

[0018] In one possible implementation, the DC-DC converter is also used for:

[0019] During the voltage conversion of the DC power supplied by the DC bus, when the voltage at the bus connection terminal decreases from greater than the target voltage to less than or equal to the target voltage, or when the duration of the current at the battery connection terminal being greater than or equal to the first current threshold is less than the fourth duration, the voltage at the bus connection terminal is adjusted, and the DC power supplied by the battery module is converted to supply power to the DC bus, so as to adjust the duration of the current at the battery connection terminal being greater than or equal to the first current threshold to be greater than or equal to the fourth duration.

[0020] In this embodiment, during the voltage conversion of the DC power supplied by the DC bus by the DC-DC converter, if the voltage at the bus connection terminal decreases from greater than the target voltage to less than or equal to the target voltage, or if the duration for which the current at the battery connection terminal is greater than or equal to the first current threshold is less than the fourth duration, it indicates that the DC bus has insufficient power after charging the lithium battery module through the DC-DC converter, meaning the DC bus cannot continuously charge the lithium battery module. At this time, the DC-DC converter can convert the DC power supplied by the lithium battery module and supply it to the DC bus, while simultaneously adjusting the voltage at the bus connection terminal to regulate the discharge current of the battery module, thereby regulating the current at the battery connection terminal and preventing the battery module from entering a sleep mode. This implementation principle is simple. Furthermore, the DC-DC converter controls the battery module to switch from charging to discharging, preventing voltage drops caused by insufficient power from the DC bus, making it highly applicable.

[0021] In one possible implementation, when the current at the battery connection terminal is less than a first current threshold for a duration greater than or equal to a first duration, the DC-DC converter adjusts the current at the battery connection terminal to be greater than or equal to the first current threshold, specifically including:

[0022] When the duration of the current at the battery connection terminal being less than the first current threshold is greater than or equal to the first duration, the DC-DC converter adjusts the voltage at the busbar connection terminal when the voltage at the battery connection terminal is greater than or equal to the rated charging voltage of the battery module, or when the voltage at the busbar connection terminal is less than or equal to the target voltage of the DC busbar, and then converts the DC power supplied by the battery module to supply power to the DC busbar, so as to adjust the current at the battery connection terminal to be greater than or equal to the first current threshold.

[0023] In this embodiment, the voltage at the battery connection terminal is greater than or equal to the rated charging voltage of the battery module, indicating that the battery module is fully charged. The voltage at the busbar connection terminal is less than or equal to the target voltage of the DC busbar, indicating that the DC busbar is in a state of insufficient power. At this time, the DC-DC converter transforms the DC power supplied by the battery module and supplies it to the DC busbar, which helps increase the DC busbar voltage to the target voltage, making it highly applicable. Simultaneously, during the voltage transformation of the DC power supplied by the battery module, the DC-DC converter can adjust the discharge current of the battery module by adjusting the voltage at the busbar connection terminal, thereby adjusting the current at the battery connection terminal, making the principle simple.

[0024] In one possible implementation, the first current threshold is greater than the second current threshold, and the first duration is less than the fifth duration; when the current at the battery connection terminal is less than or equal to the second current threshold for a duration greater than or equal to the fifth duration, the battery module enters a sleep mode; when the battery module enters a sleep mode, the battery connection terminal is disconnected from the battery pack of the battery module.

[0025] In this embodiment, the triggering condition for the battery module to enter sleep mode includes the duration for which the charging / discharging current of the battery module is less than or equal to a second current threshold being greater than or equal to a fifth duration. To prevent the battery module from entering sleep mode, the DC-DC converter can be set to have a first current threshold greater than the second current threshold and a first duration less than the fifth duration. Therefore, when the DC-DC converter detects that the current at the battery connection terminal is less than the first current threshold for a duration greater than or equal to the first duration, and the charging / discharging current of the battery module is also less than the first current threshold for a duration greater than or equal to the first duration, the aforementioned sleep mode triggering condition has not yet been met, and the battery module has not entered sleep mode. At this time, the DC-DC converter can adjust the current or voltage at the battery connection terminal to ensure that the aforementioned sleep mode triggering condition is not met, thereby ensuring that the battery module will not enter sleep mode, resulting in high reliability.

[0026] In one possible implementation, the second duration and the fourth duration are greater than or equal to the sixth duration; before the duration during which the current at the battery connection terminal is less than or equal to the second current threshold is greater than or equal to the fifth duration, when the current at the battery connection terminal increases from less than or equal to the second current threshold to greater than the second current threshold, and the duration during which the current at the battery connection terminal is greater than the second current threshold is greater than or equal to the sixth duration, the battery connection terminal remains connected to the battery pack of the battery module.

[0027] In this embodiment, the sixth duration represents the minimum duration during which the battery module can detect current changes. For example, before the duration for which the current at the battery connection is less than or equal to the second current threshold is greater than or equal to the fifth duration (i.e., the trigger condition for the battery module to enter sleep mode has not yet been met), if the DC-DC converter adjusts the duration of the current increase at the battery connection to be less than the sixth duration, the battery module cannot detect the increase in charging and discharging current because the duration of the current increase is too short. Therefore, the battery module still determines that the charging and discharging current is less than or equal to the second current threshold until the duration is greater than or equal to the fifth duration, at which point it enters sleep mode. Thus, by setting the second and fourth durations to be greater than or equal to the sixth duration, the DC-DC converter can ensure that the battery module can detect the current increase when the duration of the current increase at the battery connection is adjusted to the second or sixth duration, thereby ensuring that the trigger condition for the battery module to enter sleep mode is not met, resulting in high reliability.

[0028] In one possible implementation, the first current threshold is greater than the second current threshold, the first voltage threshold is greater than the second voltage threshold, and the third duration is greater than the seventh duration; when the current at the battery connection terminal is less than or equal to the second current threshold, and the duration for which the voltage at the battery connection terminal is less than or equal to the second voltage threshold is greater than or equal to the seventh duration, the battery module enters a sleep mode; when the battery module enters a sleep mode, the battery connection terminal is disconnected from the battery pack of the battery module.

[0029] In this embodiment, the triggering conditions for the battery module to enter sleep mode include the battery module's charging / discharging current being less than or equal to a second current threshold, and the duration for which the voltage at the battery module's output terminal is less than or equal to a second voltage threshold being greater than or equal to a seventh duration. To prevent the battery module from entering sleep mode, the DC-DC converter can be set to have a first current threshold greater than the second current threshold, a first voltage threshold greater than the second voltage threshold, and a third duration greater than the seventh duration. Therefore, when the DC-DC converter detects that the current at the battery connection terminal is less than the first current threshold and the voltage at the battery connection terminal is less than the first voltage threshold, the triggering conditions for the battery module to enter sleep mode have not yet been met, and the battery module has not yet entered sleep mode. At this time, the DC-DC converter adjusts the duration for which the voltage at the battery connection terminal is greater than or equal to the first voltage threshold to the third duration, ensuring that the aforementioned sleep mode triggering conditions are not met, thereby ensuring that the battery module will not enter sleep mode, resulting in high reliability.

[0030] In one possible implementation, the first current threshold is greater than 1 amp, the first voltage threshold is greater than 36 volts, the first duration is less than 1 hour, the second duration is greater than 1 second, the third duration is greater than 5 seconds, and the fourth duration is greater than 1 second.

[0031] In this embodiment, the specific values ​​of the first current threshold, the first voltage threshold, the first duration, the second duration, the third duration, and the fourth duration can be flexibly adjusted according to actual needs, making it applicable to a wide range of scenarios and highly adaptable.

[0032] Secondly, this application also provides a communication base station power supply system, which includes a battery module, a DC bus, and a DC-DC converter. The bus connection terminal of the DC-DC converter is connected to the DC bus, and the battery connection terminal of the DC-DC converter is connected to the battery module. The DC-DC converter is used to convert the DC power supplied by the battery module into voltage and supply it to the DC bus, or to convert the DC power supplied by the DC bus into voltage and supply it to the battery module for charging. The DC-DC converter is also used for:

[0033] When the duration for which the current at the battery connection terminal is less than the first current threshold is less than the first duration, and the voltage at the battery connection terminal is less than the first voltage threshold, the duration for which the current at the battery connection terminal is greater than or equal to the first current threshold is adjusted to the second duration, or the duration for which the voltage at the battery connection terminal is greater than or equal to the first voltage threshold is adjusted to the third duration.

[0034] When the duration for which the current at the battery connection terminal is less than the first current threshold is greater than or equal to the first duration, the duration for which the current at the battery connection terminal is greater than or equal to the first current threshold is adjusted to the fourth duration.

[0035] In one possible implementation, the battery module includes a BMS, a switching unit, and a battery pack. The battery pack is connected to the output terminal of the battery module via the switching unit, and the output terminal of the battery module is connected to a battery terminal. The BMS is used for:

[0036] When the current at the output terminal of the battery module is less than or equal to the second current threshold for a duration greater than or equal to the fifth duration, the control switch unit is normally off, so that the battery module enters a sleep mode; the first current threshold is greater than the second current threshold, and the first duration is less than the fifth duration.

[0037] In one possible implementation, the BMS is also used for:

[0038] Before the current at the output terminal of the battery module is less than or equal to the second current threshold for a duration greater than or equal to the second duration, when the current at the output terminal of the battery module increases from less than or equal to the second current threshold to greater than the second current threshold, and the duration of the current at the output terminal of the battery module being greater than the second current threshold is greater than or equal to the sixth duration, the control switch unit remains normally closed so that the battery module does not enter the sleep mode; the second duration and the fourth duration are greater than the sixth duration.

[0039] In one possible implementation, the battery module includes a BMS, a switching unit, and a battery pack. The battery pack is connected to the output terminal of the battery module via the switching unit, and the output terminal of the battery module is connected to a battery terminal. The BMS is used for:

[0040] When the current at the output terminal of the battery module is less than or equal to the second current threshold, and the duration for which the voltage at the output terminal of the battery module is less than or equal to the second voltage threshold is greater than or equal to the seventh duration, the control switch unit is normally off, so that the battery module enters sleep mode; the first current threshold is greater than the second current threshold, the first voltage threshold is greater than the second voltage threshold, and the third duration is greater than the seventh duration.

[0041] Thirdly, this application also provides a control method for a DC-DC converter, applied to a DC-DC converter, wherein the busbar connection terminal of the DC-DC converter is used to connect to the DC busbar of the power supply system of the communication base station, and the battery connection terminal of the DC-DC converter is used to connect to a battery module; the DC-DC converter is used to convert the DC power supplied by the battery module into voltage and supply it to the DC busbar, or to convert the DC power supplied by the DC busbar into voltage and supply it to the battery module for charging; the method includes:

[0042] When the duration for which the current at the battery connection terminal is less than the first current threshold is less than the first duration, and the voltage at the battery connection terminal is less than the first voltage threshold, the duration for which the current at the battery connection terminal is greater than or equal to the first current threshold is adjusted to the second duration, or the duration for which the voltage at the battery connection terminal is greater than or equal to the first voltage threshold is adjusted to the third duration.

[0043] When the duration for which the current at the battery connection terminal is less than the first current threshold is greater than or equal to the first duration, the duration for which the current at the battery connection terminal is greater than or equal to the first current threshold is adjusted to the fourth duration.

[0044] In one possible implementation, when the duration for which the current at the battery connection terminal is less than a first current threshold is less than a first duration, and the voltage at the battery connection terminal is less than a first voltage threshold, adjusting the current at the battery connection terminal to be greater than or equal to the first current threshold specifically includes:

[0045] When the duration for which the current at the battery connection terminal is less than the first current threshold is less than the first duration, and the voltage at the battery connection terminal is less than the first voltage threshold, the DC-DC converter adjusts the voltage at the battery connection terminal and provides the DC power supplied by the DC bus to the battery module for charging, so as to adjust the current at the battery connection terminal to be greater than or equal to the first current threshold.

[0046] In one possible implementation, when the duration for which the current at the battery connection terminal is less than a first current threshold is less than a first duration, and the voltage at the battery connection terminal is less than a first voltage threshold, adjusting the voltage at the battery connection terminal to be greater than or equal to the first voltage threshold specifically includes:

[0047] When the duration for which the current at the battery connection terminal is less than the first current threshold is less than the first duration, and the voltage at the battery connection terminal is less than the first voltage threshold, the DC-DC converter adjusts the voltage at the battery connection terminal and converts the DC power supplied by the DC bus to charge the battery module, thereby adjusting the voltage at the battery connection terminal to be greater than or equal to the first voltage threshold.

[0048] In one possible implementation, when the duration for which the current at the battery connection terminal is less than a first current threshold is greater than or equal to a first duration, adjusting the current at the battery connection terminal to be greater than or equal to the first current threshold specifically includes:

[0049] When the duration of the current at the battery connection terminal being less than the first current threshold is greater than or equal to the first duration, and the voltage at the battery connection terminal is less than the rated charging voltage of the battery module, while the voltage at the busbar connection terminal is greater than the target voltage of the DC busbar, the DC converter adjusts the voltage at the battery connection terminal and converts the DC power supplied by the DC busbar to charge the battery module, thereby adjusting the current at the battery connection terminal to be greater than or equal to the first current threshold.

[0050] In one possible implementation, the method further includes:

[0051] During the voltage conversion of the DC power supplied by the DC bus, when the voltage at the bus connection terminal decreases from greater than the target voltage to less than or equal to the target voltage, or when the duration of the current at the battery connection terminal being greater than or equal to the first current threshold is less than the fourth duration, the voltage at the bus connection terminal is adjusted, and the DC power supplied by the battery module is converted to supply power to the DC bus, so as to adjust the duration of the current at the battery connection terminal being greater than or equal to the first current threshold to be greater than or equal to the fourth duration.

[0052] In one possible implementation, when the duration for which the current at the battery connection terminal is less than a first current threshold is greater than or equal to a first duration, adjusting the current at the battery connection terminal to be greater than or equal to the first current threshold specifically includes:

[0053] When the duration of the current at the battery connection terminal being less than the first current threshold is greater than or equal to the first duration, the DC-DC converter adjusts the voltage at the busbar connection terminal when the voltage at the battery connection terminal is greater than or equal to the rated charging voltage of the battery module, or when the voltage at the busbar connection terminal is less than or equal to the target voltage of the DC busbar, and then converts the DC power supplied by the battery module to supply power to the DC busbar, so as to adjust the current at the battery connection terminal to be greater than or equal to the first current threshold.

[0054] In one possible implementation, the first current threshold is greater than the second current threshold, and the first duration is less than the fifth duration; when the current at the battery connection terminal is less than or equal to the second current threshold for a duration greater than or equal to the fifth duration, the battery module enters a sleep mode; when the battery module enters a sleep mode, the battery connection terminal is disconnected from the battery pack of the battery module.

[0055] In one possible implementation, the second duration and the fourth duration are greater than or equal to the sixth duration; before the duration during which the current at the battery connection terminal is less than or equal to the second current threshold is greater than or equal to the fifth duration, when the current at the battery connection terminal increases from less than or equal to the second current threshold to greater than the second current threshold, and the duration during which the current at the battery connection terminal is greater than the second current threshold is greater than or equal to the sixth duration, the battery connection terminal remains connected to the battery pack of the battery module.

[0056] In one possible implementation, the first current threshold is greater than the second current threshold, the first voltage threshold is greater than the second voltage threshold, and the third duration is greater than the seventh duration; when the current at the battery connection terminal is less than or equal to the second current threshold, and the duration for which the voltage at the battery connection terminal is less than or equal to the second voltage threshold is greater than or equal to the seventh duration, the battery module enters a sleep mode; when the battery module enters a sleep mode, the battery connection terminal is disconnected from the battery pack of the battery module.

[0057] In one possible implementation, the first current threshold is greater than 1 amp, the first voltage threshold is greater than 36 volts, the first duration is less than 1 hour, the second duration is greater than 1 second, the third duration is greater than 5 seconds, and the fourth duration is greater than 1 second.

[0058] The beneficial effects of the solutions provided in the second and third aspects above can be referred to the description in the first aspect above, and will not be repeated here. Attached Figure Description

[0059] Figure 1 A schematic diagram of an application scenario for the power supply system for the communication base station provided in this application;

[0060] Figure 2a This is a schematic diagram illustrating an application scenario of the DC-DC converter provided in an embodiment of this application.

[0061] Figure 2b This is a schematic diagram illustrating another application scenario of the DC-DC converter provided in the embodiments of this application;

[0062] Figure 3 This is a schematic diagram of the structure of a lithium battery module provided in an embodiment of this application;

[0063] Figure 4a A schematic diagram of current change at the battery connection terminal of a DC-DC converter provided in an embodiment of this application;

[0064] Figure 4b Another schematic diagram of current change at the battery connection terminal of the DC-DC converter provided in the embodiments of this application;

[0065] Figure 5a This is another schematic diagram showing the current change at the battery connection terminal of the DC-DC converter provided in the embodiments of this application;

[0066] Figure 5b This is another schematic diagram showing the current change at the battery connection terminal of the DC-DC converter provided in the embodiments of this application;

[0067] Figure 6 A schematic diagram of a voltage change at the battery connection terminal of a DC-DC converter provided in an embodiment of this application;

[0068] Figure 7a This is a schematic diagram of an electrical signal change at the battery connection terminal of a DC-DC converter provided in an embodiment of this application;

[0069] Figure 7b Another schematic diagram of electrical signal changes at the battery connection terminal of the DC-DC converter provided in the embodiments of this application;

[0070] Figure 8 This is a flowchart illustrating the control method for the DC-DC converter provided in this application. Detailed Implementation

[0071] The communication base station power supply system provided in this application is used to supply power to the load within the base station and is applicable to different application scenarios, such as energy storage power supply scenarios, photovoltaic-storage hybrid power supply scenarios, and uninterruptible power supply scenarios. The following explanation uses the energy storage power supply scenario as an example.

[0072] Please see Figure 1 , Figure 1 This is a schematic diagram illustrating an application scenario of the communication base station power supply system provided in this application. Figure 1In a communication base station power supply system, a DC bus and a rectifier are included. The rectifier's input is connected to the power grid, and its output is connected to the DC bus. The rectifier converts AC power from the grid into DC power and transmits it to the DC bus. The DC bus then transmits and distributes this DC power to the various loads of the base station, such as the antenna system, radio frequency unit, baseband unit, and related supporting systems, to supply power to the base station. It should be noted that when the power grid is shut down due to maintenance, natural disasters (such as typhoons or earthquakes causing power line interruptions), the rectifier cannot obtain power from the grid to supply the DC bus. Consequently, the DC bus cannot supply power to the base station's loads, resulting in a power outage for the base station. In the event of a power outage, the base station ceases operation, communication network signals within its coverage area are interrupted, and the normal operation of communication equipment is affected. To ensure power supply to the base station during grid outages, the communication base station power supply system also includes a battery module connected to the DC bus. When the grid is operating stably, the battery module draws DC power from the DC bus for charging. When a power outage occurs in the power grid, the battery module discharges power to the DC bus, ensuring a continuous supply of power to the base station's load and preventing communication network interruptions due to base station malfunction. Furthermore, even when there is no power outage, power fluctuations in the power grid cause fluctuations in the DC bus's power output. If these DC bus power fluctuations directly affect the base station's load, they could lead to load restarts or even damage. Therefore, the battery module can also charge and discharge during DC bus power fluctuations to absorb or compensate for these fluctuations, ensuring the reliability and stability of the communication base station power supply system. It is understood that the battery module can perform many other functions in the communication base station power supply system, which will not be listed here.

[0073] Specifically, in Figure 1In the application scenario shown, the battery modules in the communication base station power supply system include lead-acid battery modules and lithium battery modules. Lithium battery modules are widely used in traditional communication base station power supply systems due to their low cost, mature technology, and high reliability. Compared to lead-acid battery modules, lithium battery modules have higher energy density, longer cycle life, better high-temperature performance, and higher charge / discharge efficiency. Therefore, current communication base station power supply systems are gradually increasing the use of lithium battery modules. It should be noted that when a communication base station power supply system uses a mix of lead-acid and lithium battery modules, if both are directly connected to the DC bus, voltage differences will exist between the different battery modules due to variations in their charge / discharge characteristics, capacity, and internal resistance, leading to circulating currents. These circulating currents cause the battery modules to charge and discharge each other, resulting in energy waste, accelerated battery aging, and even overheating risks. To solve the circulating current problem caused by mixed power supply, a DC-DC converter can be installed between each lithium battery module and the DC bus in the communication base station power supply system. This DC-DC converter can convert the voltage of the lithium battery module to match the voltage of the DC bus and isolate the electrical connection between lithium battery modules, thereby eliminating circulating current and enabling intelligent hybrid power supply and smooth upgrades for communication base station power supply systems. Furthermore, the DC-DC converter can control the lithium battery modules to perform cycle discharge and capacity matching, tiered power backup, and tiered charging according to instructions from the upper-level controller (or built-in logic), and provide real-time data of the lithium battery modules (such as charging / discharging current, voltage, temperature, or warning information) to the upper-level controller, allowing maintenance personnel to monitor the operating status of the lithium battery modules at any time. Depending on the needs of the actual application scenario, the DC-DC converter can be used to implement various other power auxiliary functions, which will not be illustrated in detail in this embodiment.

[0074] It should be noted that lithium battery modules typically have a Battery Management System (BMS) internally for intelligent management of the charging and discharging process. This BMS manages the charging and discharging process of the lithium battery module according to the specifications defined by the battery manufacturer. For example, when the lithium battery module is idle, the BMS controls it to enter a sleep mode to reduce power consumption and prevent damage from over-discharge. However, during the process of the DC-DC converter controlling the lithium battery module for cycle discharge, capacity assessment, tiered backup power, or tiered charging, the lithium battery module may maintain a very low charging and discharging current. When the lithium battery module maintains a consistently low charging and discharging current, the BMS may determine that the lithium battery module is idle and trigger it to enter a sleep mode. At this time, if a power outage occurs in the communication base station's power supply system, the voltage of the DC bus will drop because the lithium battery module cannot supply power to the DC bus in sleep mode, leading to a load power failure.

[0075] Based on this, this application provides a DC-DC converter and its control method. The DC-DC converter can prevent the battery module from entering a sleep mode during the control of the battery module, ensuring the stability of the power supply to the communication base station, with high reliability and strong applicability.

[0076] The above are merely examples of application scenarios for the DC-DC converter provided in this application, and are not exhaustive. This application does not limit the application scenarios.

[0077] The following content combines Figures 1 to 7b The specific implementation principle of the DC-DC converter provided in the embodiments of this application will be introduced.

[0078] In this embodiment, the communication base station power supply system includes one or more battery modules, and each battery module is connected to a DC bus via a corresponding DC-DC converter. Each DC-DC converter, while controlling the operation of its connected battery module, can prevent the battery module from entering a sleep mode. The specific implementation methods for each DC-DC converter to prevent the battery module from entering a sleep mode are similar. Specific types of battery modules include lithium iron phosphate batteries, ternary lithium batteries, lithium cobalt oxide batteries, and lithium manganese oxide batteries, which can be collectively referred to as lithium battery modules. Furthermore, the specific type of battery module can be flexibly adjusted according to actual needs; this embodiment will not provide specific examples. For ease of understanding, the following description uses a DC-DC converter in a communication base station power supply system, with the battery module being a lithium battery module, as an example.

[0079] Please refer to the following for details. Figure 1 , Figure 2a and Figure 2b , Figure 2a This is a schematic diagram illustrating an application scenario of the DC-DC converter provided in an embodiment of this application. Figure 2b This is a schematic diagram illustrating another application scenario of the DC-DC converter provided in the embodiments of this application. Figure 2a and Figure 2b In the DC-DC converter, the busbar connection terminal i1 is connected to the DC busbar. This DC busbar is used to obtain power from battery modules (such as lithium battery modules or lead-acid battery modules) or to obtain power from the grid through a rectifier, and to distribute the power to the base station's load (such as...). Figure 1 (As shown). The battery connector i2 of the DC-DC converter is connected to the lithium battery module.

[0080] In this embodiment, the DC-DC converter is used to convert the DC power supplied by the DC bus and then provide it to the lithium battery module for charging. For example, during off-peak electricity hours (usually late at night), the grid load is low and electricity prices are cheap. The DC-DC converter can reduce energy storage costs by converting the DC power supplied by the DC bus and then providing it to the lithium battery module for charging. Specifically, the DC bus obtains grid power through a rectifier and transmits it to the bus connection terminal i1 of the DC-DC converter. The DC-DC converter boosts or bucks the DC power input to the bus connection terminal i1 and outputs it to the battery connection terminal i2 to charge the lithium battery module. At this time, the current flow direction of the battery connection terminal i2 of the DC-DC converter is as follows... Figure 2a As shown in Ia. Furthermore, the DC-DC converter is also used to convert the DC power supplied by the lithium battery module to supply power to the DC bus. For example, during peak electricity price periods (typically daytime and evening), when grid load is high and electricity costs are expensive, the DC-DC converter can reduce power supply costs by converting the DC power supplied by the lithium battery module to supply power to the DC bus. Alternatively, when a grid fault occurs, the DC-DC converter can ensure continuous and stable power supply by converting the DC power supplied by the lithium battery module to supply power to the DC bus, avoiding impact on load operation. Specifically, the DC-DC converter boosts or bucks the DC power input at battery connection terminal i2 and outputs it to bus connection terminal i1 to control the lithium battery module's power supply to the DC bus. At this time, the current flow at battery connection terminal i2 of the DC-DC converter is as follows... Figure 2b As shown in Ib.

[0081] In some feasible implementations, the DC-DC converter can also control the lithium battery module to perform a capacity test according to instructions from the upper-level controller (or built-in logic) during operation, in order to detect the actual capacity and charge / discharge characteristics of the lithium battery module. Specifically, the DC-DC converter can first convert the DC power supplied by the DC bus to a voltage before supplying it to the lithium battery module for charging (e.g., ...). Figure 2a (As shown), then the DC power supplied by the lithium battery module is voltage-converted and supplied to the DC bus to allow the lithium battery module to discharge (as shown). Figure 2b (As shown). Furthermore, during the charging and discharging process of the lithium battery module, the DC-DC converter can adjust the charging and discharging current of the lithium battery module (e.g., adjust the lithium battery module to charge and discharge at a constant current) to ensure accurate core capacity testing of the lithium battery module.

[0082] It should be noted that in some applications, DC-DC converters are also used to control the lithium battery module to stop charging and discharging, or to control the charging and discharging current of the lithium battery module to be very small. For example, when the power grid is operating stably, the DC bus can obtain power from the grid through a rectifier to supply power to the load. The lithium battery module, as a backup power source, does not need to supply power to the DC bus. Therefore, the DC-DC converter can control the lithium battery module to stop charging and discharging, or to control the charging and discharging current to be very small, so that the lithium battery module enters a backup power state. In the backup power state, the lithium battery module can remain fully charged or at a high charge level, ready to supply power to the DC bus in the event of a power outage. Alternatively, in other applications, because the cycle life of lithium battery modules and lead-acid battery modules is different, communication base station power supply systems usually prioritize the charging and discharging of lead-acid batteries. When lead-acid batteries are prioritized for charging and discharging, the DC-DC converter can control the lithium battery module to stop charging and discharging, or to control the charging and discharging current of the lithium battery module to be very small, to avoid circulating current between the lead-acid battery and the lithium battery module. Alternatively, when the lead-acid battery is discharged and its capacity is verified in the power supply system of the communication base station, the lithium battery module is in a non-capacitance state (i.e., the current state of the lithium battery module is not suitable for or cannot be accurately discharged and verified). The DC-DC converter can control the lithium battery module to stop charging and discharging or control the charging and discharging current of the lithium battery module to be very small, thereby avoiding the generation of circulating current between the lead-acid battery and the lithium battery module, which would affect the test results of the discharge capacity verification of the lead-acid battery.

[0083] In summary, the DC-DC converter can control the charging or discharging of the lithium battery module according to the needs of the actual application scenario. Simultaneously, when the lithium battery module is idle (e.g., when it is in standby mode, not under full capacity, or when lead-acid batteries are being preferentially charged or discharged), the DC-DC converter can control the lithium battery module to stop charging or discharging, or control the charging and discharging current to be very small, to avoid circulating current and ensure the hybrid intelligent power supply of the communication base station power supply system. It is understood that the DC-DC converter can also be used to help achieve other power auxiliary functions, which will not be illustrated in detail in this application.

[0084] As described above, the lithium battery module contains a Battery Management System (BMS). This BMS collects the module's operating parameters in real time (such as the current, voltage, temperature, state of charge, and state of power of each cell) to achieve intelligent management of the charging and discharging process. For details, please refer to [link to relevant documentation]. Figure 3 , Figure 3 This is a schematic diagram of the structure of a lithium battery module provided in an embodiment of this application. Figure 3In this design, the lithium battery module has two output terminals: output terminal O1 and output terminal O2. Output terminal O1 is connected to the battery connection terminal i21 of the DC-DC converter, and output terminal O2 is connected to the battery connection terminal i22 of the DC-DC converter. The lithium battery module internally includes a BMS, a switching unit, and a battery pack. The battery pack consists of multiple cells connected in series and parallel. The positive terminal of the battery pack is connected to the output terminal O1 of the lithium battery module via the switching unit, and the negative terminal of the battery pack is connected to the output terminal O2 of the lithium battery module. The switching unit includes a discharge switch Q1 and a charging switch Q2. When the BMS controls the discharge switch Q1 to be off and the charging switch Q2 to be on, the DC-DC converter can convert the DC power supplied by the DC bus and provide it to the battery pack for charging, thus charging the lithium battery module (e.g., ...). Figure 2a (As shown). When the BMS controls the discharge switch Q1 to be turned on and the charging switch Q2 to be turned off, the DC-DC converter can convert the DC power supplied by the battery pack into voltage and supply power to the DC bus, thus discharging the lithium battery module (e.g., ...). Figure 2b (As shown). Therefore, the BMS can control the discharge switch Q1 and charge switch Q2 in the switching unit to turn on or off, enabling the lithium battery module to charge or discharge. Furthermore, as mentioned above, the BMS can also trigger the lithium battery module to enter a sleep mode when the lithium battery is idle, thereby reducing the power consumption of the lithium battery module in the idle state and preventing damage caused by over-discharge. Specifically, the BMS can control... Figure 3 Both the discharge switch Q1 and the charging switch Q2 shown are turned off, thus shutting down the switching unit. With the switching unit off, the battery connection terminal i2 of the battery pack and the DC-DC converter is disconnected. There is no longer power exchange between the battery pack and the DC-DC converter, so the battery pack cannot be charged or discharged through the DC-DC converter. This reduces the power consumption of the lithium battery module in idle state, allowing the lithium battery module to enter a sleep mode. It should be noted that the specific internal structure of the lithium battery module can be flexibly adjusted according to actual needs. Figure 3 The examples shown are merely illustrative and do not constitute a limitation on the embodiments of this application.

[0085] In some feasible implementations, the BMS can adjust the charging and discharging current of the lithium battery module during operation, i.e., the current at the output terminal of the lithium battery module (e.g., ...). Figure 3The BMS determines whether the lithium battery module is idle by detecting the current at output terminals O1 or O2, and then decides whether to control the lithium battery module to enter sleep mode. It should be noted that when the lithium battery module is idle, there is almost no charging or discharging activity, and the power exchange between the lithium battery module and the load is very small, resulting in a consistently small current at the lithium battery module's output terminal. For example, the output current of the lithium battery module is continuously equal to 0 when charging and discharging stops. Therefore, the BMS can determine that the lithium battery module is idle by detecting a consistently small current at its output terminal. In some application scenarios, specifically, when the duration of the current at the lithium battery module's output terminal being less than or equal to a second current threshold is greater than or equal to a fifth duration, the current at the lithium battery module's output terminal is consistently small, meaning the lithium battery module is idle. The specific values ​​of the second current threshold and the fifth duration can be flexibly adjusted according to the needs of the actual application scenario. For example, the second current threshold is equal to 1 amp, and the fifth duration is equal to 1 hour.

[0086] It is understandable that lithium battery modules may over-discharge and be damaged when idle. Therefore, the BMS can control the lithium battery module to enter a sleep mode after determining that it is idle and may over-discharge. However, as mentioned above, if a power outage occurs in the communication base station power supply system after the lithium battery module enters sleep mode, the voltage of the DC bus will drop because the lithium battery cannot supply power to the DC bus in sleep mode, leading to a load power failure. Therefore, in this embodiment, the DC-DC converter monitors the operating status of the lithium battery module in real time and actively adjusts it when the lithium battery module may be idle to prevent it from entering sleep mode. As mentioned above, when the lithium battery module is idle, the duration for which the current at the output terminal of the lithium battery module is less than or equal to the second current threshold is greater than or equal to the fifth duration. Simultaneously, when the lithium battery module is connected to the battery connection terminal i2 of the DC-DC converter, the current flowing through the battery connection terminal i2 is equivalent to the current at the output terminal of the lithium battery module. Therefore, when the DC-DC converter detects that the current flowing through the battery connection terminal i2 is less than or equal to the second current threshold for a duration greater than or equal to the fifth duration, it can determine that the lithium battery module is in an idle state. When the lithium battery module is in an idle state, the internal BMS of the lithium battery module may be about to, or has already, controlled the lithium battery module to enter a sleep mode. To ensure that the lithium battery module does not enter a sleep mode, the DC-DC converter can actively adjust as early as possible when it detects that the lithium battery module may be entering an idle state. At this time, the lithium battery module may not actually be in an idle state yet; therefore, the early active adjustment by the DC-DC converter can ensure that the BMS does not control the lithium battery module to enter a sleep mode.

[0087] Specifically, when the current at battery connection terminal i2 is less than the first current threshold for a duration greater than or equal to the first duration, the current flowing through battery connection terminal i2 remains relatively small, meaning the current at the lithium battery module output terminal remains relatively small, and the lithium battery module may enter an idle state. The specific values ​​of the first current threshold and the first duration are related to the conditions for the lithium battery module to enter an idle state. For example, as mentioned above, the condition for the lithium battery module to enter an idle state is that the current at the lithium battery module output terminal is less than or equal to the second current threshold for a duration greater than or equal to the fifth duration. Therefore, when the first current threshold is greater than the second current threshold and the first duration is less than the fifth duration, if the current flowing through battery connection terminal i2 is less than the first current threshold for a duration greater than or equal to the first duration, the lithium battery module may not necessarily meet the conditions for entering an idle state, but the current at the lithium battery module output terminal remains relatively small, so the lithium battery module may be in an idle state. For example, with the second current threshold at 1 amp and the fifth duration at 1 hour, the DC-DC converter can be set to a first current threshold of 3 amps and a first duration of 0.5 hours. Understandably, when the DC-DC converter detects that the current at the battery connection terminal i2 is less than 3 amps for a duration greater than or equal to 0.5 hours, and the current at the lithium battery module output terminal remains relatively small, but the current at the lithium battery module output terminal may not necessarily meet the requirement of being less than 1 amp for a duration greater than or equal to 1 hour, the DC-DC converter determines that the lithium battery module may be in an idle state. It should be noted that the specific values ​​of the first current threshold and the first duration can be flexibly adjusted based on the second current threshold and the fifth duration; specific examples are not provided in this application.

[0088] Furthermore, when the DC-DC converter detects that the lithium battery module may be entering an idle state, it can actively increase the current at the lithium battery module's output terminal to prevent the lithium battery module from entering a sleep mode. The reason the DC-DC converter actively increases the current at the lithium battery module's output terminal is that the current at the lithium battery module's output terminal is consistently very small in the idle state, allowing the BMS to determine whether the lithium battery module is in an idle state based on the current magnitude. Therefore, when the DC-DC converter controls the increase of the current at the lithium battery module's output terminal, the BMS will determine that the lithium battery module is not idle and will not control the lithium battery module to enter a sleep mode.

[0089] Specifically, after determining that the lithium battery module may be idle, the DC-DC converter can adjust the current at the battery connection terminal i2 to be greater than or equal to a first current threshold, thereby increasing the output current of the lithium battery module. However, due to the limited accuracy of the BMS in sampling the output current of the lithium battery module, if the duration of the output current being greater than or equal to the first current threshold is very short, the BMS may not detect it and will still determine that the lithium battery module is idle. Therefore, the DC-DC converter adjusts the duration of the current at the battery connection terminal i2 being greater than or equal to the first current threshold to a fourth duration, ensuring that the output current of the lithium battery module is greater than or equal to the first current threshold for the fourth duration. If the current at the lithium battery module output terminal is greater than or equal to the first current threshold for a duration exceeding four time intervals, the BMS can detect the increase in the lithium battery module output current and will reset the duration of the current being less than the first current threshold to zero. Therefore, the BMS cannot detect the current continuously being less than the first current threshold, and thus will not determine that the lithium battery module is in an idle state. For example, if the BMS detects that the current at the lithium battery module output terminal is less than or equal to 1 amp for a duration of 0.2 hours, and then the DC-DC converter increases the current at the lithium battery module output terminal to 3 amps for a duration less than 1 second, the BMS cannot detect the increase in current because the duration of the current increase is too short. Therefore, the BMS still determines that the current at the lithium battery module output terminal is continuously less than or equal to 1 amp and continues to record the duration of the current being less than or equal to 1 amp. Conversely, when the current at the lithium battery module output increases to 3 amps for a duration greater than or equal to 1 second, the BMS can detect the change in the lithium battery module current (i.e., the current is no longer consistently less than or equal to 1 amp), and thus reset the duration (0.2 hours) of the current at the lithium battery module output being less than or equal to 1 amp to zero. Therefore, by adjusting the duration of the current at the battery connection terminal being greater than or equal to the first current threshold to a fourth duration, the DC-DC converter can cause the BMS to reset the record of the duration of the current at the lithium battery module output being less than the first current threshold to zero. Consequently, the BMS cannot determine that the lithium battery module is in an idle state and will not control the lithium battery module to enter sleep mode.

[0090] In some feasible implementations, the specific value of the fourth duration is related to the current sampling accuracy of the BMS. The DCDC converter can determine the specific value of the fourth duration by determining the current sampling accuracy of the BMS through multiple experiments. Specifically, as mentioned above, when the duration of the current at battery connection terminal i2 being less than or equal to the second current threshold is greater than or equal to the fifth duration, the lithium battery module is in an idle state, and the BMS can control the lithium battery module to enter a sleep mode. Therefore, in order to determine the current sampling accuracy of the BMS, the DCDC converter can adjust the current at battery connection terminal i2 from less than or equal to the second current threshold to greater than the second current threshold before the duration of the current at battery connection terminal i2 being less than or equal to the second current threshold is greater than or equal to the fifth duration (i.e., before the lithium battery module enters the sleep mode), and adjust the duration of the current at battery connection terminal i2 being greater than the second current threshold to be greater than or equal to the sixth duration. Understandably, if the current sampling accuracy of the BMS is not met during the sixth duration (i.e., the BMS cannot detect current changes within the sixth duration), the BMS cannot detect that the current at the lithium battery output terminal is greater than the second current threshold. Therefore, the BMS will continue to record the duration for which the current at the lithium battery module output terminal is less than or equal to the second current threshold until this duration is greater than or equal to the fifth duration, at which point it will control the lithium battery module to enter sleep mode. Conversely, if the current sampling accuracy of the BMS is met during the sixth duration, the BMS can detect that the charging and discharging current of the lithium battery is greater than the second current threshold. Therefore, the BMS will reset the duration for which the current at the lithium battery module output terminal is less than or equal to the second current threshold to zero. Thus, the BMS cannot determine that the lithium battery module is in an idle state and will not control it to enter sleep mode. Therefore, the DC-DC converter can determine whether the sixth duration meets the BMS's current sampling accuracy by observing whether the lithium battery module enters sleep mode while adjusting the sixth duration. Furthermore, after determining that the sixth duration meets the BMS's current sampling accuracy, the DC-DC converter can set the fourth duration to be greater than the sixth duration. When the DC-DC converter adjusts the current at the battery connection terminal i2 to be greater than or equal to the first current threshold for a duration of four hours, the current at the lithium battery module output terminal can also be greater than or equal to the first current threshold for a duration of four hours. Since this fourth duration is longer than the sixth duration, the BMS can detect the current change within this fourth duration and thus clear the record of the duration during which the current at the lithium battery module output terminal is less than the first current threshold. Therefore, the BMS cannot determine that the lithium battery module is in an idle state and will not control the lithium battery module to enter sleep mode.

[0091] In some feasible implementations, when the DC-DC converter detects that the lithium battery module may be entering an idle state, if the voltage at battery connection terminal i2 is less than the rated charging voltage of the lithium battery module, and the voltage at bus connection terminal i1 is greater than the target voltage of the DC bus, the DC-DC converter can adjust the voltage at battery connection terminal i2 and convert the DC power supplied by the DC bus to charge the lithium battery module. This adjusts the duration for which the current at battery connection terminal i2 is greater than or equal to the first current threshold to a fourth duration. It should be noted that when the voltage at battery connection terminal i2 is less than the rated charging voltage of the lithium battery module, it indicates that the output voltage of the lithium battery module is less than the rated charging voltage, meaning the lithium battery module is not fully charged. At this time, the charging voltage provided by the DC-DC converter to the lithium battery module is greater than or equal to the rated charging voltage of the lithium battery module, allowing the lithium battery module to charge. Simultaneously, the voltage at bus connection terminal i1 being greater than the target voltage of the DC bus indicates that the DC bus is in a state of surplus power. Therefore, the DC-DC converter converts the DC power supplied by the DC bus to a voltage before supplying it to the lithium battery module, thus reducing the DC bus voltage to the target voltage. It can be seen that when the DC-DC converter detects that the voltage at battery connection terminal i2 is less than the rated charging voltage of the lithium battery module, and the voltage at bus connection terminal i1 is greater than the target voltage of the DC bus, it converts the DC power supplied by the DC bus to a voltage before supplying it to the lithium battery module. This not only regulates the current at battery connection terminal i2 to be greater than or equal to the first current threshold, but also effectively regulates the DC bus voltage while simultaneously charging the lithium battery module.

[0092] For example, please refer to Figure 4a and Figure 4b , Figure 4a This is a schematic diagram of a current change at the battery connection terminal of a DC-DC converter provided in an embodiment of this application. Figure 4b This is another schematic diagram of current change at the battery connection terminal of the DC-DC converter provided in the embodiments of this application. Figure 4a and Figure 4b The difference is that, in Figure 4a In the process, before the current at the battery connection terminal is less than the first current threshold I1, the current flowing through the battery connection terminal is the charging current of the lithium battery module (e.g., ...). Figure 2a As shown in 4b, before the current at the battery connection terminal is less than the first current threshold I1, the current flowing through the battery connection terminal is the discharge current of the lithium battery module (e.g., Figure 2b (As shown). In Figure 4a and Figure 4bIn the process where the duration of the current at the battery connection terminal being less than the first current threshold I1 is greater than or equal to the first duration t1, and the voltage at the battery connection terminal is less than the rated charging voltage of the lithium battery module, and the voltage at the busbar connection terminal is greater than the target voltage of the DC busbar, the DC-DC converter adjusts the voltage at the battery connection terminal and converts the DC power supplied by the DC busbar to provide voltage for charging the lithium battery module (the current flow direction at the battery connection terminal is as follows...). Figure 2a As shown, the current at the battery connection terminal is adjusted to be greater than or equal to a first current threshold I1, thereby ensuring that the charging current of the lithium battery module is greater than or equal to the first current threshold I1. Simultaneously, the DC-DC converter adjusts the duration for which the current at the battery connection terminal is greater than or equal to the first current threshold I1 to a fourth duration t4, so that the BMS resets the duration for which the current of the lithium battery module is less than the first current threshold I1 (i.e., the first duration t1) to zero. Therefore, the BMS will not detect that the lithium battery module is in an idle state, thus avoiding controlling the lithium battery module to enter a sleep mode.

[0093] In some feasible implementations, when the DC-DC converter detects that the voltage at battery connection terminal i2 is less than the rated charging voltage of the lithium battery module, and the voltage at bus connection terminal i1 is greater than the target voltage of the DC bus, when the DC-DC converter adjusts the voltage at battery connection terminal i2 and provides the DC power supplied by the DC bus to the lithium battery module for charging, thereby adjusting the current at battery connection terminal i2 to be greater than or equal to a first current threshold, if the voltage at bus connection terminal i1 decreases from greater than the target voltage of the DC bus to less than or equal to the target voltage, it indicates that the DC bus is experiencing insufficient power when charging the lithium battery module through the DC-DC converter, i.e., the DC bus cannot be continuously used to charge the lithium battery module. Alternatively, during the process of the DC-DC converter providing power from the DC bus to the lithium battery module for charging, if the duration for which the current at battery connection terminal i2 is greater than or equal to the first current threshold is less than a fourth duration, it also indicates that the DC target power is insufficient and cannot sustain charging the lithium battery module to the fourth duration. At this point, if the DC-DC converter continues to control the lithium battery module's charging, it may cause a voltage drop in the DC bus. Furthermore, because it cannot maintain the current at battery connection i2 above the first current threshold for the fourth duration, the lithium battery module will inevitably enter a sleep mode. Therefore, the DC-DC converter can switch from controlling the lithium battery module's charging to controlling its discharging. Specifically, the DC-DC converter can adjust the voltage at bus connection i1 and convert the DC power supplied by the lithium battery module before supplying it to the DC bus. This adjusts the current at battery connection i2 to be greater than or equal to the first current threshold for the fourth duration, ensuring that the BMS does not control the lithium battery module to enter a sleep mode and preventing a voltage drop due to insufficient power on the DC bus. During this process, the current at battery connection i2 is adjusted from... Figure 2a The switch shown is to Figure 2b As shown.

[0094] In some feasible implementations, when the lithium battery module may enter an idle state, if the DC-DC converter detects that the voltage at the battery connection terminal i2 is greater than or equal to the rated charging voltage of the lithium battery module, it indicates that the output voltage of the lithium battery module is greater than or equal to the rated charging voltage, meaning the lithium battery module is in a fully charged state. At this time, the DC-DC converter can adjust the voltage at the bus connection terminal i1 and convert the DC power supplied by the lithium battery module to supply power to the DC bus, thus preventing overcharging of the lithium battery module. Simultaneously, it adjusts the duration for which the current at the battery connection terminal i2 is greater than or equal to the first current threshold to a fourth duration. Alternatively, when the lithium battery module may enter an idle state, if the DC-DC converter detects that the voltage at the bus connection terminal i1 is less than or equal to the target voltage of the DC bus, it indicates that there is no surplus power on the DC bus, meaning the DC bus cannot be used to continuously supply charging power to the lithium battery module. At this time, in order to avoid voltage drop caused by insufficient power on the DC bus, the DC-DC converter can adjust the voltage of the bus connection terminal i1 and convert the DC power provided by the lithium battery module to supply power to the DC bus, so as to adjust the duration of the current at the battery connection terminal i2 being greater than or equal to the first current threshold to the fourth duration, ensuring that the BMS will not control the lithium battery module to enter the sleep mode.

[0095] For example, please refer to Figure 5a and Figure 5b , Figure 5a This is another schematic diagram showing the current change at the battery connection terminal of the DC-DC converter provided in the embodiments of this application. Figure 5b This is another schematic diagram of current change at the battery connection terminal of the DC-DC converter provided in the embodiments of this application. Figure 5a and Figure 5b The difference is that, in Figure 5a In the process, before the current at the battery connection terminal is less than the first current threshold I1, the current flowing through the battery connection terminal is the charging current of the lithium battery module (e.g., ...). Figure 2a As shown in 5b, before the current at the battery connection terminal is less than the first current threshold I1, the current flowing through the battery connection terminal is the discharge current of the lithium battery module (e.g., Figure 2b (As shown). In Figure 5a and Figure 5b In the process, when the current at the battery connection terminal is less than the first current threshold I1 for a duration greater than or equal to the first duration t1, and the voltage at the battery connection terminal is greater than or equal to the rated charging voltage of the lithium battery module, or when the voltage at the busbar connection terminal is less than or equal to the target voltage of the DC busbar, the DC-DC converter adjusts the voltage at the busbar connection terminal and converts the DC power supplied by the lithium battery module to supply power to the DC busbar (the current flow direction at the battery connection terminal is as follows). Figure 2bAs shown, the current at the battery connection terminal is adjusted to be greater than or equal to the first current threshold I1. Simultaneously, the DC-DC converter adjusts the duration for which the current at the battery connection terminal is greater than or equal to the first current threshold I1 to a fourth duration t4, so that the BMS resets the duration for which the current of the lithium battery module is less than the first current threshold I1 (i.e., the first duration t1) to zero. Therefore, the BMS will not detect that the lithium battery module is in an idle state, thereby avoiding controlling the lithium battery module to enter a sleep mode.

[0096] In some feasible implementations, as described above, the DC-DC converter determines whether the lithium battery module is likely to enter an idle state by detecting current changes at the battery connection terminal i2, while the BMS determines this by detecting current changes during charging and discharging. When there is no communication connection between the DC-DC converter and the BMS, if the current detection of the DC-DC converter and the BMS is asynchronous, the DC-DC converter may fail to detect that the lithium battery module has entered an idle state, even though the lithium battery module is already in an idle state. This results in the DC-DC converter failing to prevent the lithium battery module from entering a sleep mode. Therefore, in this embodiment, the DC-DC converter can combine the voltage and current changes at the battery connection terminal i2 to comprehensively determine whether it is necessary to actively adjust the current or voltage at the output terminal of the lithium battery module to prevent the lithium battery module from entering a sleep mode.

[0097] In some feasible implementations, as described above, after detecting that the lithium battery module is in an idle state, the BMS can further detect whether the lithium battery module will over-discharge in this idle state, thereby determining whether it is necessary to control the lithium battery module to enter a sleep mode. For details, please refer to... Figure 3As shown, when the BMS detects that the lithium battery module is in an idle state, it can first control the switching unit to turn off. With the switching unit off, the battery pack is disconnected from the output terminal of the lithium battery module. The voltage at the output terminal of the lithium battery module (i.e., the voltage difference between output terminals o1 and o2) is determined by the voltage at the battery connection terminal i2. It should be noted that if the DC-DC converter can obtain sufficient power from the DC bus to charge the lithium battery module, the voltage at the battery connection terminal i2 will remain relatively high, and consequently, the voltage at the output terminal of the lithium battery module will also remain relatively high. Therefore, if the BMS detects a consistently high voltage at the output terminal of the lithium battery module when the switching unit is off, it indicates that the lithium battery module can still obtain charging power in an idle state. In this case, the lithium battery module will not over-discharge, and the BMS does not need to control the lithium battery module to enter a sleep mode. Conversely, if the DC-DC converter cannot obtain sufficient power from the DC bus to charge the lithium battery module (e.g., when the DC bus voltage is less than or equal to the target voltage), the voltage at the battery connection terminal i2 of the DC-DC converter will remain low, and consequently, the voltage at the output terminal of the lithium battery module will also remain low. Therefore, if the BMS detects a persistently low output voltage of the lithium battery module when the switching unit is off, it indicates that the lithium battery module cannot obtain sufficient charging power in the idle state, potentially leading to over-discharge. To prevent over-discharge of the lithium battery module, the BMS needs to keep the switching unit normally off to control the lithium battery module into a sleep mode. For example, when the switching unit is off, if the BMS detects that the lithium battery module's output voltage is less than or equal to the second voltage threshold for a duration greater than or equal to the seventh duration, it determines that the lithium battery module cannot obtain sufficient charging power in this idle state, potentially leading to over-discharge, and thus requires controlling the lithium battery module to enter a sleep mode. The specific values ​​of the second voltage threshold and the seventh duration can be flexibly adjusted according to the needs of the actual application scenario. For example, the second voltage threshold is equal to 36 volts and the seventh duration is equal to 5 seconds.

[0098] Understandably, when the current detection of the DC-DC converter and the BMS is asynchronous, if the DC-DC converter detects that the current at battery connection i2 is less than the first current threshold for a duration less than the first duration, the DC-DC converter may not detect that the lithium battery module may be in an idle state. However, the BMS may have already detected that the lithium battery module is in an idle state. In this case, to prevent the BMS from controlling the lithium battery module to enter a sleep mode, the DC-DC converter can adjust the voltage at battery connection i2 in a timely manner before detecting that the current at battery connection i2 is less than the first current threshold for a duration less than the first duration, and the voltage at battery connection i2 is less than or equal to the second voltage threshold for a duration greater than or equal to the seventh duration. This ensures that the voltage at the output of the lithium battery module does not meet the above-mentioned over-discharge conditions (i.e., the voltage at the output of the lithium battery module is less than or equal to the second voltage threshold for a duration greater than or equal to the seventh duration), thereby preventing the BMS from controlling the lithium battery module to enter a sleep mode.

[0099] Specifically, the DC-DC converter can be preset with a first current threshold, a first voltage threshold, and a third duration, wherein the first current threshold is greater than the aforementioned second current threshold, the first voltage threshold is greater than the aforementioned second voltage threshold, and the third duration is greater than the aforementioned seventh duration. Further, when the DC-DC converter detects that the current at battery connection terminal i2 is less than the first current threshold for a duration less than the first duration, and the voltage at battery connection terminal i2 is less than the first voltage threshold, the BMS may have detected that the lithium battery module is in an idle state and may have already controlled the switching unit to disconnect. To prevent the BMS from detecting that the voltage at the output terminal of the lithium battery module meets the aforementioned over-discharge condition, the DC-DC converter can adjust the duration for which the voltage at battery connection terminal i2 is greater than or equal to the first voltage threshold to the third duration, so that the voltage at the output terminal of the lithium battery module is greater than or equal to the first voltage threshold for a duration greater than or equal to the third duration. Since the first voltage threshold is greater than the second voltage threshold, and the third duration is greater than the seventh duration, the BMS cannot determine that the voltage at the output terminal of the lithium battery module meets the aforementioned over-discharge conditions. In other words, the BMS determines that the lithium battery module is not in an idle state that would cause over-discharge, and therefore will not control the lithium battery module to enter sleep mode. Thus, in this embodiment, regardless of whether the DCDC converter accurately detects that the lithium battery module has entered an idle state, the DCDC converter comprehensively determines whether to actively adjust the voltage at the output terminal of the lithium battery module by combining the voltage and current changes at the battery connection terminal i2. This ensures that the lithium battery module is prevented from entering sleep mode, resulting in high reliability.

[0100] In some feasible implementations, the DC-DC converter can adjust the voltage at the battery connection terminal i2 and convert the DC power supplied by the DC bus to charge the lithium battery module, thereby regulating the duration for which the output voltage of the lithium battery module is greater than or equal to a first voltage threshold up to a third duration. It should be noted that when the DC-DC converter detects that the voltage at the battery connection terminal i2 is less than the first voltage threshold, it converts the DC power supplied by the DC bus and adjusts the voltage at the battery connection terminal i2, rather than controlling the battery module to discharge. This is because, at this time, the BMS inside the battery module may have already controlled the switching unit to turn off, preventing the battery module from discharging. Therefore, the DC-DC converter might not be able to adjust the voltage at the battery connection terminal i2 while controlling the battery module to discharge. Thus, by converting the DC power supplied by the DC bus, the DC-DC converter can ensure that the voltage at the battery connection terminal is successfully adjusted to be greater than or equal to the first voltage threshold, ensuring that the BMS does not control the battery module to enter a sleep mode, resulting in high reliability.

[0101] For example, please refer to Figure 6 , Figure 6 This is a schematic diagram of a voltage change at the battery connection terminal of a DC-DC converter provided in an embodiment of this application. Figure 6 In this context, t0 refers to the duration during which the current at the battery connection terminal is less than the first current threshold, and t0 is less than the aforementioned first duration. At this time, the DC-DC converter does not detect that the lithium battery module may be entering an idle state. However, since the current detection of the BMS and the DC-DC converter may be asynchronous, the BMS may have already detected that the lithium battery module is in an idle state, and thus may control the lithium battery module to enter a sleep mode. To prevent the BMS from controlling the lithium battery module to enter a sleep mode, within t0, when the DC-DC converter detects that the voltage at the battery connection terminal is less than the first voltage threshold V1, the DC-DC converter adjusts the duration during which the voltage at the battery connection terminal is greater than or equal to the first voltage threshold V1 to a third duration t3. It can be understood that at this time, even if the BMS has detected that the lithium battery module is in an idle state, because the duration during which the voltage at the battery connection terminal is greater than or equal to the first voltage threshold V1 is greater than or equal to the third duration, the BMS cannot detect that the lithium battery module is in an idle state that may cause over-discharge. Therefore, the BMS will not control the lithium battery module to enter a sleep mode.

[0102] In some feasible implementations, when the current detection of the DC-DC converter and the current detection of the BMS are not synchronized, if the DC-DC converter detects that the current at battery connection terminal i2 is less than the first current threshold for a duration less than a first duration, and the voltage at battery connection terminal i2 is less than the first voltage threshold, the DC-DC converter does not detect that the lithium battery module may be entering an idle state. In reality, the BMS may have already detected that the lithium battery is in an idle state, but the BMS has not yet controlled the switching unit to disconnect, or the BMS may not have detected that the lithium battery is in an idle state. At this time, if the lithium battery module is fully charged, to prevent the BMS from detecting that the voltage at the output terminal of the lithium battery module meets the above-mentioned over-discharge conditions, the DC-DC converter can adjust the voltage at battery connection terminal i2 and convert the DC power provided by the DC bus to charge the lithium battery module, thereby adjusting the duration of the voltage at battery connection terminal i2 being greater than or equal to the first current threshold to a third duration. This prevents the BMS from detecting that the lithium battery module is in an idle state that may cause over-discharge, and the BMS will not control the lithium battery module to enter a sleep mode. It should be noted that when the voltage at the battery connection terminal i2 is less than the first voltage threshold, the DC-DC converter performs voltage conversion on the voltage provided by the DC bus to adjust the voltage at the battery connection terminal to be greater than or equal to the first voltage threshold. This prevents the battery module from entering a sleep mode and reduces the power loss of the battery module. Specifically, the implementation principle of the DC-DC converter is the same as described above. Figure 6 The specific implementation methods are similar and will not be described in detail here.

[0103] In some feasible implementations, when the current detection of the DC-DC converter and the current detection of the BMS are not synchronized, if the DC-DC converter detects that the current at battery connection i2 is less than the first current threshold for a duration less than a first duration, and the voltage at battery connection i2 is less than the first voltage threshold, the DC-DC converter may not detect that the lithium battery module may be in an idle state. However, the BMS may have already detected that the lithium battery is in an idle state, but the BMS has not yet controlled the switching unit to disconnect, or the BMS may not have detected that the lithium battery is in an idle state. In this case, if the lithium battery module is not fully charged, to prevent the BMS from detecting that the voltage at the output terminal of the lithium battery module meets the aforementioned over-discharge condition, the DC-DC converter can adjust the voltage at battery connection i2 and charge the lithium battery module by converting the DC power provided by the DC bus. This adjusts the duration for which the current at battery connection i2 is greater than or equal to the first current threshold to a second duration, thereby ensuring that the current at the output terminal of the lithium battery module is greater than or equal to the first current threshold for a duration greater than or equal to the second duration. At this point, as mentioned above, the BMS cannot detect that the lithium battery module is in an idle state, therefore the BMS will not control the lithium battery module to enter sleep mode. The second duration is longer than the sixth duration mentioned above. The specific value of this second duration is similar to that of the fourth duration mentioned above, and will not be elaborated upon here.

[0104] It should be noted that when the DC-DC converter detects that the voltage at the battery connection terminal i2 is less than the first voltage threshold, the DC-DC converter adjusts the voltage at the battery connection terminal i2 and supplies the power from the DC bus to the battery module to charge it in order to regulate the current at the battery connection terminal, rather than controlling the battery module to discharge. This can prevent the battery module from being over-discharged due to insufficient power.

[0105] For example, please refer to Figure 7a and Figure 7b , Figure 7a This is a schematic diagram of an electrical signal change at the battery connection terminal of a DC-DC converter provided in an embodiment of this application. Figure 7b This is a schematic diagram of another electrical signal change at the battery connection terminal of the DC-DC converter provided in an embodiment of this application. Figure 7a and Figure 7b The difference is that, in Figure 7a In the process, before the current at the battery connection terminal is less than the first current threshold I1, the current flowing through the battery connection terminal is the charging current of the lithium battery module (e.g., ...). Figure 2a As shown in 7b, before the current at the battery connection terminal is less than the first current threshold I1, the current flowing through the battery connection terminal is the discharge current of the lithium battery module (e.g., Figure 2b (As shown). In Figure 7a and Figure 7bIn this context, t0 refers to the duration during which the current at the battery connection terminal is less than the first current threshold I1, and t0 is less than the aforementioned first duration. Within t0, when the DC-DC converter detects that the voltage at the battery connection terminal is less than the first voltage threshold V1, the DC-DC converter adjusts the voltage at the battery connection terminal and converts the DC power supplied by the DC bus to voltage before supplying it to the lithium battery module for charging. At this time, since the lithium battery module is not fully charged, the battery connection terminal can transmit charging current to the lithium battery module. Simultaneously, the DC-DC converter can adjust the duration during which the current at the battery connection terminal is greater than the first current threshold I1 to a second duration t2, so that the BMS cannot detect that the lithium battery module is in an idle state, thereby preventing the BMS from controlling the lithium battery module to enter a sleep mode. Furthermore, since the electrical energy supplied to the lithium battery module by the DC-DC converter is mainly used to charge the lithium battery module, the voltage at the battery connection terminal will not continuously increase.

[0106] In summary, in the embodiments of this application, when the current detection of the BMS and the DC-DC converter is asynchronous, the DC-DC converter can combine the voltage and current changes at the battery connection terminal i2 to comprehensively determine whether it is necessary to actively adjust the current or voltage at the output terminal of the lithium battery module, so as to prevent the BMS from controlling the lithium battery module to enter a sleep mode. In other words, the DC-DC converter does not need to communicate with the battery module to effectively prevent the battery module from entering a sleep mode, demonstrating strong applicability.

[0107] Please see Figure 8 , Figure 8 This is a flowchart illustrating the control method for the DC-DC converter provided in this application. The control method for the DC-DC converter provided in this embodiment is applicable to... Figures 1 to 7b The corresponding specific implementation of the DC-DC converter. Specifically, the control method of the DC-DC converter may include the following steps:

[0108] S101. When the duration for which the current at the battery connection terminal is less than the first current threshold is less than the first duration, and the voltage at the battery connection terminal is less than the first voltage threshold, adjust the duration for which the current at the battery connection terminal is greater than or equal to the first current threshold to the second duration, or adjust the duration for which the voltage at the battery connection terminal is greater than or equal to the first voltage threshold to the third duration.

[0109] It is understandable that the battery module may enter a sleep mode when idle, in which it stops charging and discharging to reduce power consumption. However, the DC bus in the communication base station power supply system may require power from the battery module at any time, so it is necessary to prevent the battery module from entering a sleep mode. The triggering condition for the battery module to enter a sleep mode includes a continuously low charging and discharging current. Therefore, this embodiment can promptly increase the charging and discharging current of the battery module when it is detected to be relatively low, so that the charging and discharging current cannot remain continuously low (i.e., the triggering condition for entering a sleep mode cannot be met), thus preventing the battery module from entering a sleep mode. Simultaneously, since the battery connection terminal of the DC-DC converter is connected to the battery module, the DC-DC converter can determine whether the charging and discharging current of the battery module is relatively low by detecting the current at the battery connection terminal. In this embodiment, when the duration of the current at the battery connection terminal being less than a first current threshold is greater than or equal to a first duration, the charging and discharging current of the battery module is considered to be relatively low. At this time, the DC-DC converter actively adjusts the duration for which the current at the battery connection terminal is greater than or equal to the first current threshold to the fourth duration, so that the charging and discharging current of the battery module cannot remain very small, thus preventing the battery module from entering the sleep mode.

[0110] For a detailed implementation of S101, please refer to the above. Figures 1 to 7b The implementation method of the DC-DC converter is not described in detail in the embodiments of this application.

[0111] S102. When the duration of the current at the battery connection terminal being less than the first current threshold is greater than or equal to the first duration, adjust the duration of the current at the battery connection terminal being greater than or equal to the first current threshold to the fourth duration.

[0112] It is understandable that, due to the lack of communication between the battery module and the DC-DC converter, their current detection may be asynchronous, causing the DC-DC converter to be unable to effectively prevent the battery module from entering sleep mode. Therefore, the DC-DC converter can comprehensively determine whether to actively adjust the battery module's charging and discharging based on changes in voltage and current at the battery connection terminal. Specifically, when the current at the battery connection terminal is less than a first current threshold for a duration less than a first duration, and the voltage at the battery connection terminal is less than a first voltage threshold, the charging and discharging current of the battery module may already be relatively low. In this case, the DC-DC converter can actively adjust the current at the battery connection terminal to be greater than or equal to the first current threshold for a second duration, preventing the charging and discharging current of the battery module from remaining consistently low and thus preventing it from entering sleep mode. Alternatively, the DC-DC converter can actively adjust the voltage at the battery connection terminal to be greater than or equal to the first voltage threshold for a third duration, allowing the battery module to determine that the DC-DC converter can provide charging voltage, thus preventing the battery module from entering sleep mode. Therefore, in this embodiment, the DC-DC converter does not need a communication connection with the battery module to effectively prevent the battery module from entering sleep mode, demonstrating strong applicability. Furthermore, the DC-DC converter adjusts the duration of the increased current at the battery connection to a second or fourth duration. This is because if the duration of the increased current is too short, the battery module may not be able to detect the increase. Therefore, by adjusting the duration of the increased current to a second or fourth duration, the battery module can accurately detect the increased current. This allows the battery module to effectively and accurately detect that the charging / discharging current exceeds the trigger condition for entering sleep mode (i.e., the current exceeds the first current threshold), ensuring that the battery module does not enter sleep mode and thus ensuring high reliability.

[0113] For a detailed implementation of S102, please refer to the above. Figures 1 to 7b The implementation method of the DC-DC converter is not described in detail in the embodiments of this application.

[0114] In an optional implementation, when the duration for which the current at the battery connection terminal is less than a first current threshold is less than a first duration, and the voltage at the battery connection terminal is less than a first voltage threshold, adjusting the current at the battery connection terminal to be greater than or equal to the first current threshold specifically includes:

[0115] When the current at the battery connection terminal is less than a first current threshold for a duration less than a first duration, and the voltage at the battery connection terminal is less than a first voltage threshold, the DC-DC converter adjusts the voltage at the battery connection terminal and converts the DC power supplied by the DC bus to charge the battery module, thereby adjusting the current at the battery connection terminal to be greater than or equal to the first current threshold. It can be understood that when the battery module is not fully charged, the DC-DC converter converts the DC power supplied by the DC bus to charge the battery module, generating a charging current. During this process, the DC-DC converter can adjust the charging current of the battery module by adjusting the voltage at the battery connection terminal. Since the charging current is the same as the current flowing through the battery connection terminal, adjusting the voltage at the battery connection terminal by the DC-DC converter directly adjusts the current at the battery connection terminal, making the principle simple. Furthermore, when the voltage at the battery connection terminal is less than the first voltage threshold, the battery module may have insufficient power. Therefore, the DC-DC converter controls the charging of the battery module to adjust the current at the battery connection terminal, preventing over-discharge of the battery module.

[0116] In an optional implementation, when the duration for which the current at the battery connection terminal is less than a first current threshold is less than a first duration, and the voltage at the battery connection terminal is less than a first voltage threshold, adjusting the voltage at the battery connection terminal to be greater than or equal to the first voltage threshold specifically includes:

[0117] When the duration for which the current at the battery connection terminal is less than the first current threshold is less than the first duration, and the voltage at the battery connection terminal is less than the first voltage threshold, the DC-DC converter adjusts the voltage at the battery connection terminal and converts the DC power supplied by the DC bus to charge the battery module, thereby adjusting the voltage at the battery connection terminal to be greater than or equal to the first voltage threshold.

[0118] Understandably, when the battery module is fully charged, if the DC-DC converter converts the DC power supplied by the DC bus to a higher voltage and then supplies it to the battery module, the battery module cannot continue charging. The charging energy provided by the DC-DC converter will cause the battery module's charging voltage to rise. During this process, the DC-DC converter can directly adjust the voltage at the battery connection point, making the principle simple. Furthermore, if the voltage at the battery connection point is lower than a first voltage threshold, the DC-DC converter can adjust the voltage at the battery connection point to be greater than or equal to the first voltage threshold by converting the voltage supplied by the DC bus. This prevents the battery module from entering a sleep mode and reduces the battery module's energy loss.

[0119] In an optional implementation, when the duration for which the current at the battery connection terminal is less than a first current threshold is greater than or equal to a first duration, adjusting the current at the battery connection terminal to be greater than or equal to the first current threshold specifically includes:

[0120] When the duration of the current at the battery connection terminal being less than the first current threshold is greater than or equal to the first duration, and the voltage at the battery connection terminal is less than the rated charging voltage of the battery module, while the voltage at the busbar connection terminal is greater than the target voltage of the DC busbar, the DC converter adjusts the voltage at the battery connection terminal and converts the DC power supplied by the DC busbar to charge the battery module, thereby adjusting the current at the battery connection terminal to be greater than or equal to the first current threshold.

[0121] Understandably, a voltage at the battery connection terminal lower than the battery module's rated charging voltage indicates that the battery module is not fully charged, while a voltage at the busbar connection terminal higher than the target voltage of the DC busbar indicates that the DC busbar has excess power. In this case, the DC-DC converter transforms the DC power supplied by the DC busbar and provides it to the battery module for charging. This effectively adjusts the DC busbar voltage to the target voltage, thus charging the lithium battery module, making it highly versatile. Furthermore, during the voltage transformation process of the DC power supplied by the DC busbar, the DC-DC converter can adjust the charging current of the battery module by regulating the voltage at the battery connection terminal, thereby regulating the current at the battery connection terminal. The principle is simple.

[0122] In an optional implementation, the method further includes:

[0123] During the voltage conversion of the DC power supplied by the DC bus, when the voltage at the bus connection terminal decreases from greater than the target voltage to less than or equal to the target voltage, or when the duration of the current at the battery connection terminal being greater than or equal to the first current threshold is less than the fourth duration, the voltage at the bus connection terminal is adjusted, and the DC power supplied by the battery module is converted to supply power to the DC bus, so as to adjust the duration of the current at the battery connection terminal being greater than or equal to the first current threshold to be greater than or equal to the fourth duration.

[0124] Understandably, during the voltage conversion process of the DC power supplied by the DC bus by the DC-DC converter, if the voltage at the bus connection terminal decreases from greater than the target voltage to less than or equal to the target voltage, or if the duration for which the current at the battery connection terminal is greater than or equal to the first current threshold is less than the fourth duration, it indicates that the DC bus is experiencing insufficient power after charging the lithium battery module through the DC-DC converter. In other words, the DC bus cannot continuously charge the lithium battery module. At this time, the DC-DC converter can convert the DC power supplied by the lithium battery module and supply it to the DC bus, while simultaneously adjusting the voltage at the bus connection terminal to regulate the discharge current of the battery module, thereby regulating the current at the battery connection terminal and preventing the battery module from entering a sleep mode. This is a simple implementation. Furthermore, the DC-DC converter controls the battery module to switch from charging to discharging, preventing voltage drops caused by insufficient power from the DC bus, making it highly versatile.

[0125] In an optional implementation, when the duration for which the current at the battery connection terminal is less than a first current threshold is greater than or equal to a first duration, adjusting the current at the battery connection terminal to be greater than or equal to the first current threshold specifically includes:

[0126] When the duration of the current at the battery connection terminal being less than the first current threshold is greater than or equal to the first duration, the DC-DC converter adjusts the voltage at the busbar connection terminal when the voltage at the battery connection terminal is greater than or equal to the rated charging voltage of the battery module, or when the voltage at the busbar connection terminal is less than or equal to the target voltage of the DC busbar, and then converts the DC power supplied by the battery module to supply power to the DC busbar, so as to adjust the current at the battery connection terminal to be greater than or equal to the first current threshold.

[0127] Understandably, a voltage at the battery connection terminal greater than or equal to the rated charging voltage of the battery module indicates that the battery module is fully charged, while a voltage at the busbar connection terminal less than or equal to the target voltage of the DC busbar indicates that the DC busbar is in a state of insufficient power. In this case, the DC-DC converter transforms the DC power supplied by the battery module and supplies it to the DC busbar, helping to increase the DC busbar voltage to the target voltage, thus offering broad applicability. Simultaneously, during the voltage transformation of the DC power supplied by the battery module, the DC-DC converter can adjust the discharge current of the battery module by regulating the voltage at the busbar connection terminal, thereby regulating the current at the battery connection terminal, making the principle simple.

[0128] In an optional implementation, the first current threshold is greater than the second current threshold, and the first duration is less than the fifth duration; when the current at the battery connection terminal is less than or equal to the second current threshold for a duration greater than or equal to the fifth duration, the battery module enters a sleep mode; when the battery module enters a sleep mode, the battery connection terminal is disconnected from the battery pack of the battery module.

[0129] It is understood that the triggering conditions for the battery module to enter sleep mode include the duration for which the charging / discharging current of the battery module is less than or equal to a second current threshold being greater than or equal to a fifth duration. To prevent the battery module from entering sleep mode, the DC-DC converter can be set to have a first current threshold greater than the second current threshold and a first duration less than the fifth duration. Therefore, when the DC-DC converter detects that the current at the battery connection terminal is less than the first current threshold for a duration greater than or equal to the first duration, and the charging / discharging current of the battery module is also less than the first current threshold for a duration greater than or equal to the first duration, the aforementioned sleep mode triggering conditions have not yet been met, and the battery module has not entered sleep mode. At this time, the DC-DC converter can adjust the current or voltage at the battery connection terminal to ensure that the aforementioned sleep mode triggering conditions are not met, thereby ensuring that the battery module will not enter sleep mode, resulting in high reliability.

[0130] In an optional implementation, the second duration and the fourth duration are greater than or equal to the sixth duration; before the duration during which the current at the battery connection terminal is less than or equal to the second current threshold is greater than or equal to the fifth duration, when the current at the battery connection terminal increases from less than or equal to the second current threshold to greater than the second current threshold, and the duration during which the current at the battery connection terminal is greater than the second current threshold is greater than or equal to the sixth duration, the battery connection terminal remains connected to the battery pack of the battery module.

[0131] Understandably, the sixth duration represents the minimum duration during which the battery module can detect current changes. For example, before the duration for which the current at the battery connection is less than or equal to the second current threshold is greater than or equal to the fifth duration (i.e., the trigger condition for the battery module to enter sleep mode has not yet been met), if the DC-DC converter adjusts the duration of the current increase at the battery connection to be less than the sixth duration, the battery module cannot detect the increase in charging / discharging current because the duration of the current increase is too short. Therefore, the battery module still determines that the charging / discharging current is less than or equal to the second current threshold until the duration is greater than or equal to the fifth duration, at which point it enters sleep mode. Thus, by setting the second and fourth durations to be greater than or equal to the sixth duration, the DC-DC converter can ensure that the battery module can detect the current increase when the duration of the current increase at the battery connection is adjusted to the second or sixth duration, thereby ensuring that the trigger condition for the battery module to enter sleep mode is not met, resulting in high reliability.

[0132] In an optional implementation, the first current threshold is greater than the second current threshold, the first voltage threshold is greater than the second voltage threshold, and the third duration is greater than the seventh duration; when the current at the battery connection terminal is less than or equal to the second current threshold, and the duration for which the voltage at the battery connection terminal is less than or equal to the second voltage threshold is greater than or equal to the seventh duration, the battery module enters a sleep mode; when the battery module enters a sleep mode, the battery connection terminal is disconnected from the battery pack of the battery module.

[0133] It is understood that the triggering conditions for the battery module to enter sleep mode include the battery module's charging / discharging current being less than or equal to a second current threshold, and the battery module's output voltage being less than or equal to a second voltage threshold for a duration greater than or equal to a seventh duration. To prevent the battery module from entering sleep mode, the DC-DC converter can be set to have a first current threshold greater than the second current threshold, a first voltage threshold greater than the second voltage threshold, and a third duration greater than the seventh duration. Therefore, when the DC-DC converter detects that the current at the battery connection is less than the first current threshold and the voltage at the battery connection is less than the first voltage threshold, the triggering conditions for the battery module to enter sleep mode have not yet been met, and the battery module has not yet entered sleep mode. At this time, the DC-DC converter adjusts the duration of the voltage at the battery connection being greater than or equal to the first voltage threshold to the third duration, ensuring that the aforementioned sleep mode triggering conditions are not met, thus ensuring that the battery module will not enter sleep mode, resulting in high reliability.

[0134] In an alternative implementation, the first current threshold is greater than 1 amp, the first voltage threshold is greater than 36 volts, the first duration is less than 1 hour, the second duration is greater than 1 second, the third duration is greater than 5 seconds, and the fourth duration is greater than 1 second.

[0135] Understandably, the specific values ​​of the first current threshold, the first voltage threshold, the first duration, the second duration, the third duration, and the fourth duration can be flexibly adjusted according to actual needs, making it suitable for a wide range of applications and highly applicable.

[0136] The above are merely specific embodiments of this application, but the scope of protection of this application is not limited thereto. Any changes or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application.

Claims

1. A DC-DC converter, characterized in that, The busbar connection terminal of the DC-DC converter is used to connect to the DC busbar of the communication base station power supply system, and the battery connection terminal of the DC-DC converter is used to connect to the battery module; the DC-DC converter is used to convert the DC power provided by the battery module into voltage and supply it to the DC busbar, or to convert the DC power provided by the DC busbar into voltage and supply it to charge the battery module; the DC-DC converter is also used for: When the duration for which the current at the battery connection terminal is less than the first current threshold is less than the first duration, and the duration for which the voltage at the battery connection terminal is less than the first voltage threshold is adjusted to the second duration, or the duration for which the current at the battery connection terminal is greater than or equal to the first current threshold is adjusted to the third duration. When the duration for which the current at the battery connection terminal is less than the first current threshold is greater than or equal to the first duration, the duration for which the current at the battery connection terminal is greater than or equal to the first current threshold is adjusted to a fourth duration.

2. The DC-DC converter according to claim 1, characterized in that, When the duration for which the current at the battery connection terminal is less than a first current threshold is less than the first duration, and the voltage at the battery connection terminal is less than a first voltage threshold, the DC-DC converter adjusts the current at the battery connection terminal to be greater than or equal to the first current threshold, specifically including: When the duration for which the current at the battery connection terminal is less than the first current threshold is less than the first duration, and the voltage at the battery connection terminal is less than the first voltage threshold, the DC-DC converter adjusts the voltage at the battery connection terminal and provides the DC power supplied by the DC bus to the battery module for charging after voltage conversion, so as to adjust the current at the battery connection terminal to be greater than or equal to the first current threshold.

3. The DC-DC converter according to claim 1, characterized in that, When the duration for which the current at the battery connection terminal is less than a first current threshold is less than the first duration, and the voltage at the battery connection terminal is less than a first voltage threshold, the DC-DC converter adjusts the voltage at the battery connection terminal to be greater than or equal to the first voltage threshold, specifically including: When the duration for which the current at the battery connection terminal is less than the first current threshold is less than the first duration, and the voltage at the battery connection terminal is less than the first voltage threshold, the DC-DC converter adjusts the voltage at the battery connection terminal and provides the DC power supplied by the DC bus to the battery module for charging, so as to adjust the voltage at the battery connection terminal to be greater than or equal to the first voltage threshold.

4. The DC-DC converter according to any one of claims 1 to 3, characterized in that, When the duration for which the current at the battery connection terminal is less than the first current threshold is greater than or equal to the first duration, the DC-DC converter adjusts the current at the battery connection terminal to be greater than or equal to the first current threshold, specifically including: When the duration of the current at the battery connection terminal being less than the first current threshold is greater than or equal to the first duration, and the voltage at the battery connection terminal is less than the rated charging voltage of the battery module, and the voltage at the busbar connection terminal is greater than the target voltage of the DC busbar, the DC converter adjusts the voltage at the battery connection terminal and provides the DC power supplied by the DC busbar to the battery module for charging, so as to adjust the current at the battery connection terminal to be greater than or equal to the first current threshold.

5. The DC-DC converter according to claim 4, characterized in that, The DC-DC converter is also used for: During the process of voltage conversion of the DC power supplied by the DC bus, when the voltage at the bus connection terminal decreases from greater than the target voltage to less than or equal to the target voltage, or when the duration of the current at the battery connection terminal being greater than or equal to the first current threshold is less than the fourth duration, the voltage at the bus connection terminal is adjusted, and the DC power supplied by the battery module is voltage converted and supplied to the DC bus, so as to adjust the duration of the current at the battery connection terminal being greater than or equal to the first current threshold to be greater than or equal to the fourth duration.

6. The DC-DC converter according to any one of claims 1 to 3, characterized in that, When the duration for which the current at the battery connection terminal is less than the first current threshold is greater than or equal to the first duration, the DC-DC converter adjusts the current at the battery connection terminal to be greater than or equal to the first current threshold, specifically including: When the duration of the current at the battery connection terminal being less than the first current threshold is greater than or equal to the first duration, and the voltage at the battery connection terminal of the DC-DC converter is greater than or equal to the rated charging voltage of the battery module, or when the voltage at the busbar connection terminal is less than or equal to the target voltage of the DC busbar, the DC-DC converter adjusts the voltage at the busbar connection terminal and supplies power to the DC busbar after voltage conversion of the DC power provided by the battery module, so as to adjust the current at the battery connection terminal to be greater than or equal to the first current threshold.

7. The DC-DC converter according to any one of claims 1 to 6, characterized in that, The first current threshold is greater than the second current threshold, and the first duration is less than the fifth duration; when the duration of the current at the battery connection terminal being less than or equal to the second current threshold is greater than or equal to the fifth duration, the battery module enters a sleep mode; when the battery module enters a sleep mode, the battery connection terminal is disconnected from the battery pack of the battery module.

8. The DC-DC converter according to claim 7, characterized in that, The second duration and the fourth duration are greater than or equal to the sixth duration; before the duration during which the current at the battery connection terminal is less than or equal to the second current threshold is greater than or equal to the fifth duration, when the current at the battery connection terminal increases from less than or equal to the second current threshold to greater than the second current threshold, and the duration during which the current at the battery connection terminal is greater than the second current threshold is greater than or equal to the sixth duration, the battery connection terminal remains connected to the battery pack of the battery module.

9. The DC-DC converter according to any one of claims 1 to 8, characterized in that, The first current threshold is greater than the second current threshold, the first voltage threshold is greater than the second voltage threshold, and the third duration is greater than the seventh duration; when the current at the battery connection terminal is less than or equal to the second current threshold, and the duration for which the voltage at the battery connection terminal is less than or equal to the second voltage threshold is greater than or equal to the seventh duration, the battery module enters a sleep mode; when the battery module enters a sleep mode, the battery connection terminal is disconnected from the battery pack of the battery module.

10. The DC-DC converter according to any one of claims 1 to 9, characterized in that, The first current threshold is greater than 1 amp, the first voltage threshold is greater than 36 volts, the first duration is less than 1 hour, the second duration is greater than 1 second, the third duration is greater than 5 seconds, and the fourth duration is greater than 1 second.

11. A power supply system for a communication base station, characterized in that, The communication base station power supply system includes a battery module, a DC bus, and a DC-DC converter. The bus connection terminal of the DC-DC converter is connected to the DC bus, and the battery connection terminal of the DC-DC converter is connected to the battery module. The DC-DC converter is used to convert the DC power supplied by the battery module into voltage and supply it to the DC bus, or to convert the DC power supplied by the DC bus into voltage and supply it to charge the battery module. The DC-DC converter is also used for: When the duration for which the current at the battery connection terminal is less than the first current threshold is less than the first duration, and the duration for which the voltage at the battery connection terminal is less than the first voltage threshold is adjusted to the second duration, or the duration for which the current at the battery connection terminal is greater than or equal to the first current threshold is adjusted to the third duration. When the duration for which the current at the battery connection terminal is less than the first current threshold is greater than or equal to the first duration, the duration for which the current at the battery connection terminal is greater than or equal to the first current threshold is adjusted to a fourth duration.

12. The communication base station power supply system according to claim 11, characterized in that, The battery module includes a BMS, a switching unit, and a battery pack. The battery pack is connected to the output terminal of the battery module through the switching unit. The output terminal of the battery module is connected to the battery connection terminal. The BMS is used for: When the current at the output terminal of the battery module is less than or equal to the second current threshold for a duration greater than or equal to the fifth duration, the switching unit is controlled to be normally off, so that the battery module enters a sleep mode; the first current threshold is greater than the second current threshold, and the first duration is less than the fifth duration.

13. The communication base station power supply system according to claim 12, characterized in that, The BMS is also used for: Before the current at the output terminal of the battery module is less than or equal to the second current threshold for a duration greater than or equal to the second duration, when the current at the output terminal of the battery module increases from less than or equal to the second current threshold to greater than the second current threshold, and the current at the output terminal of the battery module is greater than the second current threshold for a duration greater than or equal to the sixth duration, the switch unit is controlled to remain normally closed so that the battery module does not enter a sleep mode; the second duration and the fourth duration are greater than the sixth duration.

14. The communication base station power supply system according to any one of claims 11 to 13, characterized in that, The battery module includes a BMS, a switching unit, and a battery pack. The battery pack is connected to the output terminal of the battery module through the switching unit. The output terminal of the battery module is connected to the battery connection terminal. The BMS is used for: When the current at the output terminal of the battery module is less than or equal to the second current threshold, and the duration for which the voltage at the output terminal of the battery module is less than or equal to the second voltage threshold is greater than or equal to the seventh duration, the switching unit is controlled to be normally off, so that the battery module enters a sleep mode; the first current threshold is greater than the second current threshold, the first voltage threshold is greater than the second voltage threshold, and the third duration is greater than the seventh duration.

15. A control method for a DC-DC converter, applied to the DC-DC converter, wherein the busbar connection terminal of the DC-DC converter is used to connect to the DC busbar of a communication base station power supply system, and the battery connection terminal of the DC-DC converter is used to connect to a battery module; the DC-DC converter is used to convert the DC power supplied by the battery module into voltage and supply it to the DC busbar, or to convert the DC power supplied by the DC busbar into voltage and supply it to the battery module for charging; characterized in that, The method includes: When the duration for which the current at the battery connection terminal is less than the first current threshold is less than the first duration, and the duration for which the voltage at the battery connection terminal is less than the first voltage threshold is adjusted to the second duration, or the duration for which the current at the battery connection terminal is greater than or equal to the first current threshold is adjusted to the third duration. When the duration for which the current at the battery connection terminal is less than the first current threshold is greater than or equal to the first duration, the duration for which the current at the battery connection terminal is greater than or equal to the first current threshold is adjusted to a fourth duration.

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