Battery charging method, main controller and battery system

Abstract

The invention discloses a battery charging method, a main controller and a battery system, and relates to the technical field of battery charging, and the method comprises the steps: obtaining the current voltage of each single lead-acid battery in a lead-acid battery pack; determining a voltage difference value by using the maximum current voltage and the minimum current voltage in the current voltages; under the condition that the voltage difference value is greater than a first preset voltage difference value, controlling the single lead-acid battery corresponding to the maximum current voltage to charge an active equalization device; and after the active equalization device is charged for a preset duration, controlling the active equalization device to charge the single lead-acid battery corresponding to the minimum current voltage until the voltage difference value between the maximum current voltage and the minimum current voltage is smaller than the first preset voltage difference value. The charging safety of the lead-acid battery can be guaranteed.

Description

Technical Field

[0001] This invention relates to the field of battery charging technology, specifically to a battery charging method, a main controller, and a battery system. Background Technology

[0002] As core material handling equipment in logistics, warehousing, and manufacturing, the reliability and economy of the power source of industrial vehicles directly affect production efficiency. Currently, these vehicles generally use lead-acid battery packs as their power source. When charging lead-acid battery packs, the charging mode mainly adopted is constant current-constant voltage charging mode, which treats the lead-acid battery pack as a whole for energy input control and adjusts the charging parameters by monitoring the total voltage and current of the lead-acid battery pack.

[0003] However, charging lead-acid battery packs using the constant current-constant voltage charging mode cannot guarantee the charging safety of lead-acid batteries. Summary of the Invention

[0004] This invention aims to address one of the technical problems in related technologies to a certain extent. To this end, this invention provides a battery charging method, a main controller, and a battery system, which have the advantage of ensuring the charging safety of lead-acid batteries.

[0005] To achieve the above objectives, the present invention adopts the following technical solution: A battery charging method, applied to a main controller, includes: Obtain the current voltage of each individual lead-acid battery in the lead-acid battery pack; The voltage difference is determined using the maximum and minimum current voltages among the current voltages. When the voltage difference is greater than a first preset voltage difference, the single lead-acid battery corresponding to the maximum current voltage is controlled to charge the active balancing device; wherein, the active balancing device is an energy regulation device for balancing the voltage difference between single lead-acid batteries in the lead-acid battery pack. After charging the active balancing device for a preset time, the active balancing device is controlled to charge the single lead-acid battery corresponding to the minimum current voltage until the voltage difference between the maximum current voltage and the minimum current voltage is less than the first preset voltage difference.

[0006] Optionally, the active balancing device is connected in parallel with each of the individual lead-acid batteries. The active balancing device includes a switch driver chip, an energy storage unit, and a switch assembly corresponding to each of the individual lead-acid batteries. The step of controlling the active balancing device to charge the individual lead-acid battery corresponding to the minimum current voltage after charging the active balancing device for a preset time, until the voltage difference between the maximum current voltage and the minimum current voltage is less than the first preset voltage difference, includes: A conduction control signal is sent to the switch driver chip so that the switch driver chip conducts the switching component of the single lead-acid battery corresponding to the maximum current voltage based on the conduction control signal, thereby charging the energy storage unit; After charging the active balancing device for a preset time, a conduction control signal is sent to the switch driver chip, so that the switch driver chip conducts the switching component of the single lead-acid battery corresponding to the minimum current voltage based on the conduction control signal, and charges the single lead-acid battery corresponding to the minimum current voltage.

[0007] Optionally, the energy storage unit includes a capacitor, an inductor, and a transformer.

[0008] Optionally, after charging the active balancing device for a preset duration, controlling the active balancing device to charge the single lead-acid battery corresponding to the minimum current voltage until the voltage difference between the maximum current voltage and the minimum current voltage is less than the first preset voltage difference, further includes: Obtain the new current voltage of each individual lead-acid battery in the lead-acid battery pack; The new voltage difference is determined using the new maximum current voltage and the new minimum current voltage from the new current voltage. If the new voltage difference is greater than the first preset voltage difference, the active balancing device is used to reduce the voltage difference between the single lead-acid battery corresponding to the new maximum current voltage and the single lead-acid battery corresponding to the new minimum current voltage until the lead-acid battery pack finishes charging.

[0009] Optionally, after determining the voltage difference using the maximum and minimum current voltages, the method further includes: When the voltage difference is greater than the second preset voltage difference, the charging current is reduced by a preset charging current; wherein the second preset voltage difference is greater than the first preset low voltage difference.

[0010] Optionally, after determining the voltage difference using the maximum and minimum current voltages, the method further includes: If the voltage difference is greater than the third preset voltage difference, the charging current is reduced by a preset charging current; wherein the third preset voltage difference is greater than the second preset voltage difference; After charging the lead-acid battery pack for a preset time using the preset charging current, if the voltage difference between the maximum current voltage and the minimum current voltage is still greater than the third preset voltage difference, then the charging of the lead-acid battery pack is stopped.

[0011] Secondly, the present invention also provides a master controller, comprising: One or more processors; A memory having stored one or more computer programs thereon, which, when executed by one or more processors, cause the one or more processors to implement any of the preceding battery charging methods.

[0012] Thirdly, the present invention also provides a battery system, comprising: The battery system includes a lead-acid battery pack, a main controller, a voltage acquisition device, and an active balancing device. The lead-acid battery pack comprises multiple individual lead-acid batteries connected in series. The voltage acquisition device and the active balancing device are connected in parallel with the individual lead-acid batteries, respectively. The main controller is connected to both the active balancing device and the voltage acquisition device. The voltage acquisition device acquires the current voltage of each individual lead-acid battery under the control of the main controller; The active balancing device reduces the voltage difference between individual lead-acid batteries under the control of the main controller. The main controller is the one described above.

[0013] Optionally, the battery system further includes a charging power device and a protection device. The charging power device is connected to the controller, the lead-acid battery pack, and the mains power supply, respectively. The protection device is connected to the main controller and the charging power device, respectively. Under the control of the main controller, the charging power device reduces the charging current to a preset value. The protection device disconnects the charging circuit of the lead-acid battery pack under the control of the main controller.

[0014] Optionally, the battery system further includes an alarm device connected to the main controller. The alarm device outputs alarm information under the control of the main controller.

[0015] In this invention, during the charging process of the lead-acid battery pack, the current voltage of each individual lead-acid battery is acquired, and the individual lead-acid battery with the maximum current voltage and the individual lead-acid battery with the minimum current voltage are locked. For the individual lead-acid batteries with the maximum current voltage and the individual lead-acid batteries with the minimum current voltage, the active balancing device is used as an energy transfer carrier to perform targeted energy transfer only on the extreme value individual lead-acid batteries, so as to reduce the voltage difference between individual lead-acid batteries. This can prevent some individual lead-acid batteries from overcharging and causing water loss and bulging, or undercharging and causing sulfation, thereby effectively eliminating the safety hazards of individual lead-acid battery bulging, electrolyte leakage, or even explosion, and thus significantly improving the reliability of the lead-acid battery of the liquid supply vehicle during the charging process.

[0016] These features and advantages of the present invention will be disclosed in detail in the following specific embodiments and accompanying drawings. The preferred embodiments or means of the present invention will be shown in detail in conjunction with the accompanying drawings, but are not intended to limit the technical solutions of the present invention. In addition, each of these features, elements and components appearing in the following text and drawings is a plurality of, and different symbols or numbers are used for convenience of representation, but all represent parts with the same or similar construction or function. Attached Figure Description

[0017] The present invention will be further described below with reference to the accompanying drawings: Figure 1 This is a schematic diagram of the battery system of the present invention; Figure 2 A flowchart of one embodiment of the battery charging method provided by the present invention; Figure 3 A schematic diagram of the energy balancing process of the active balancing device provided by the present invention; Figure 4 This is a schematic diagram of the equalization process for the charging of a lead-acid battery pack provided by the present invention. Figure 5 This is a schematic flowchart illustrating the battery charging method of this embodiment performed by the battery system provided by the present invention. Figure 6 This is a schematic diagram of the structure of a master controller provided by the present invention.

[0018] Explanation of reference numerals in the attached figures: 101: Processor; 102: Memory; 103: I / O interface; 104: Bus. Detailed Implementation

[0019] Embodiments of the present invention are described in detail below, examples of which are illustrated in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described are intended to explain the present invention and should not be construed as limiting the invention.

[0020] The terms "an embodiment," "example," or "trademark" used in this specification refer to a particular feature, structure, or characteristic described in connection with the embodiment itself that may be included in at least one embodiment disclosed in this invention. The phrase "in an embodiment" appearing in various places throughout the specification does not necessarily refer to the same embodiment.

[0021] As core material handling equipment in logistics, warehousing, and manufacturing, the reliability and economy of the power source of industrial vehicles directly affect production efficiency. Currently, these vehicles generally use lead-acid battery packs as their power source. When charging lead-acid battery packs, the charging mode mainly adopted is constant current-constant voltage charging mode, which treats the lead-acid battery pack as a whole for energy input control and adjusts the charging parameters by monitoring the total voltage and current of the lead-acid battery pack.

[0022] Charging lead-acid battery packs using a constant current-constant voltage charging mode has the following drawbacks: 1. Due to differences in manufacturing processes, usage environments, and cycle life, the internal resistance and contents of individual lead-acid batteries gradually diverge. The constant current-constant voltage charging mode cannot recognize and address these differences, leading to some individual lead-acid batteries in the battery pack being undercharged for extended periods and developing sulfation, while others are overcharged and experience water loss and bulging, thus accelerating the shortening of the lead-acid battery pack's lifespan. 2. To address the issue of not being able to identify differences between individual lead-acid batteries, some battery systems have introduced passive balancing circuits. However, passive balancing circuits typically activate towards the end of charging, when the voltage difference is already significant, and they balance the voltage difference between individual lead-acid batteries by reducing the energy of high-energy individual batteries through resistive discharge. Activating the passive balancing circuit at the end of charging suffers from drawbacks such as low balancing current, low efficiency, and high heat generation. For lead-acid battery packs in industrial vehicles with high operating intensity and large capacity, the balancing effect is limited.

[0023] 3. When a single lead-acid battery is overcharged, the amount of gas produced increases significantly, which can easily lead to bulging, electrolyte drying, and even leakage or explosion.

[0024] 4. The premature failure of lead-acid battery packs due to inconsistent voltage differences between individual lead-acid batteries, coupled with frequent manual inspections and maintenance, results in high overall operating costs for users.

[0025] In view of this, to ensure the charging safety of lead-acid battery packs and reduce costs, this invention proposes a battery system, such as... Figure 1 As shown, Figure 1 This is a schematic diagram of the battery system, which includes: The system comprises a lead-acid battery pack, a main controller, a voltage acquisition device, and an active balancing device. The lead-acid battery pack includes multiple individual lead-acid batteries connected in series. The voltage acquisition device and the active balancing device are connected in parallel with the individual lead-acid batteries. The main controller is connected to both the active balancing device and the voltage acquisition device. The voltage acquisition device acquires the current voltage of each individual lead-acid battery under the control of the main controller; The active balancing device reduces the voltage difference between individual lead-acid batteries under the control of the main controller. The main controller is a main controller that can implement the battery charging method.

[0026] In this embodiment, the main controller can be an industrial-grade MCU, such as an STM32F103.

[0027] Specifically, the voltage acquisition device can be connected to the positive and negative terminals of each individual lead-acid battery via dedicated shielded leads. During the charging process of the lead-acid battery pack, the voltage acquisition device can acquire the current voltage of each individual lead-acid battery at a frequency of 100Hz. The voltage acquisition device is equipped with multiple ADC chips, such as ADS1115. After acquiring the current voltage of each individual lead-acid battery, the multiple ADC chips can accurately and frequently convert the analog voltage signal of each individual lead-acid battery into a digital signal and transmit it to the main controller.

[0028] After receiving the current voltage of each individual lead-acid battery, the main controller can determine the maximum and minimum current voltages and use these to determine the voltage difference. If the voltage difference is less than a first preset voltage difference, the lead-acid battery pack is charged normally. If the voltage difference is greater than the first preset voltage difference, the active balancing device is activated to transfer energy from the individual lead-acid battery with the maximum current voltage to the individual lead-acid battery with the minimum current voltage. Specifically, the device first controls the individual lead-acid battery with the maximum current voltage to charge the active balancing device for a preset duration. After the preset charging duration ends, the device then charges the individual lead-acid battery with the minimum current voltage until the voltage difference between the maximum and minimum current voltages is less than the first preset voltage difference.

[0029] It is worth mentioning that, in order to achieve refined control over the charging process of lead-acid battery packs and avoid excessive intervention affecting charging efficiency when the voltage difference is small, while avoiding insufficient intervention leading to safety hazards when the voltage difference is large, as an optional implementation, a charging power device and a protection device can be set in the battery system. The charging power device is connected to the controller, the lead-acid battery pack and the mains power, respectively. The protection device is connected to the main controller and the charging power device, respectively. Under the control of the main controller, the charging power device reduces the charging current to a preset charging current; the protection device disconnects the charging circuit of the lead-acid battery pack under the control of the main controller.

[0030] In this embodiment, the charging power device includes an AC / DC converter and a power MOSFET, and the protection device includes a relay or a high-power MOSFET.

[0031] Specifically, during the charging process of the lead-acid battery pack, the AC mains power can be converted into DC power compatible with the lead-acid battery pack using an AC / DC converter. When the main controller determines that the voltage difference between the current maximum and minimum voltages is greater than a second preset voltage difference, it can send a signal to the power MOSFET to reduce the charging current, such as a PWM signal. Upon receiving the PWM signal, the power MOSFET controls the charging current by adjusting its duty cycle. For example, a 100% duty cycle corresponds to a 50A rated current, and 50% corresponds to a 25A current reduction, thus reducing the charging current to 25A.

[0032] Correspondingly, if the voltage difference between the maximum and minimum current voltages exceeds a third preset voltage difference, the charging current of the lead-acid battery pack can be reduced to a preset charging current, such as reducing the charging current from the rated 50A to 25A. The lead-acid battery pack can then be charged for a preset duration using this preset charging current, such as five minutes. After charging the lead-acid battery pack for the preset duration using the preset charging current, if the voltage difference between the maximum and minimum current voltages still exceeds the third preset voltage difference, the main controller can send a protection command to the protection device, such as sending a command to disconnect the charging circuit. Upon receiving the command, the protection device will disconnect the relay or turn off the high-power MOSFET to cut off the charging circuit of the lead-acid battery pack, stopping the charging of the lead-acid battery pack and thus avoiding the risk of overcharging.

[0033] When the voltage difference between individual lead-acid batteries in a lead-acid battery pack is too large, in order to warn of potential safety hazards in advance and to reserve buffer space for operation and maintenance, as an optional implementation, the battery system also includes an alarm device. The alarm device is connected to the main controller, and the alarm device outputs alarm information under the control of the main controller.

[0034] In this embodiment, the alarm device includes an audible and visual alarm and / or a communication interface. The audible and visual alarm can be a buzzer and a warning light, and the communication interface can be a CAN bus or an RS-485 interface.

[0035] After calculating the voltage difference using the maximum and minimum current voltages, if the voltage difference is greater than the second preset voltage difference or the third preset voltage difference, the main controller sends an alarm control command to the alarm device. The alarm device then activates the audible and visual alarms based on the received alarm control command, such as activating the buzzer or turning the warning light yellow. The alarm control command is then converted into an industrial bus signal via the CAN bus or RS-485 protocol and transmitted to the remote operation and maintenance platform or the central control system of the industrial vehicle.

[0036] In this embodiment, the voltage acquisition device is connected in parallel with each individual lead-acid battery, directly acquiring the current voltage of each individual battery to provide accurate voltage data support for the main controller. Simultaneously, the main controller locks the maximum and minimum current voltages from the current voltages and calculates the voltage difference. If the voltage difference exceeds a first preset voltage difference, the individual lead-acid battery with the maximum current voltage is directed to charge the active balancing device, which then charges the individual lead-acid battery with the minimum current voltage. Compared to traditional battery systems that manage the lead-acid battery pack as a whole, this embodiment uses targeted balancing to balance the energy of the individual lead-acid batteries with the maximum and minimum current voltages. This keeps the voltage difference between individual lead-acid batteries within a first preset voltage difference, preventing overcharging leading to water loss and bulging, or undercharging leading to sulfation. It effectively suppresses the rate of differentiation in internal resistance and capacity of the lead-acid batteries, thereby ensuring the charging safety of the lead-acid batteries.

[0037] Meanwhile, this embodiment sets a first preset voltage difference value, a second preset voltage difference threshold, and a third preset voltage difference threshold. With the voltage difference value as the core control parameter, different charging measures are taken when the voltage difference value is greater than the corresponding preset voltage difference value. This not only avoids maintenance redundancy caused by excessive alarms for small risks, but also prevents safety accidents caused by insufficient warnings for large risks. It perfectly adapts to the high-frequency, high-current, and high-safety charging requirements of lead-acid batteries in industrial vehicles, thereby achieving refined management and control of the battery system.

[0038] As another aspect of the present invention, a battery charging method is provided, such as... Figure 2 As shown, the method includes: In step S110, the current voltage of each individual lead-acid battery in the lead-acid battery pack is obtained.

[0039] In step S120, the voltage difference is determined using the maximum and minimum current voltages among the current voltages.

[0040] In step S130, if the voltage difference is greater than the first preset voltage difference, the single lead-acid battery corresponding to the maximum current voltage is controlled to charge the active balancing device.

[0041] The active balancing device is an energy regulation device that balances the voltage difference between individual lead-acid batteries within a lead-acid battery pack.

[0042] In step S140, after charging the active balancing device for a preset time, the active balancing device is controlled to charge the single lead-acid battery corresponding to the minimum current voltage until the voltage difference between the maximum current voltage and the minimum current voltage is less than the first preset voltage difference.

[0043] Specifically, the voltage acquisition module can periodically acquire the current voltage of each individual lead-acid battery at a frequency of 100Hz and send the current voltage of each individual lead-acid battery to the main controller. After receiving the current voltage of each individual lead-acid battery, the main controller calculates the voltage difference using the maximum and minimum current voltages.

[0044] If the voltage difference is greater than a first preset voltage difference, the lead-acid battery cell corresponding to the maximum current voltage can be controlled to charge the active balancing device. After the lead-acid battery cell corresponding to the maximum current voltage has been charging the active balancing device for a preset time, the active balancing device is controlled to charge the lead-acid battery cell corresponding to the minimum current voltage until the voltage difference between the maximum current voltage and the minimum current voltage is less than the first preset voltage difference.

[0045] To meet the high-frequency, high-current, and high-safety charging requirements of lead-acid batteries in industrial vehicles, the active balancing module can be a capacitor-type bidirectional balancing circuit. Therefore, as an optional implementation method, refer to... Figure 3 As shown, Figure 3 A schematic diagram of the process for energy balancing of the active balancing device, specifically including step S140: In step S310, a conduction control signal is sent to the switch driver chip so that the switch driver chip conducts the switching component of the single lead-acid battery corresponding to the maximum current voltage based on the conduction control signal, thereby charging the energy storage unit.

[0046] In step S320, after charging the active balancing device for a preset duration, a conduction control signal is sent to the switch driver chip, so that the switch driver chip conducts the switching component of the single lead-acid battery corresponding to the minimum current voltage based on the conduction control signal, and charges the single lead-acid battery corresponding to the minimum current voltage.

[0047] In this embodiment, the active balancing device is connected in parallel with each of the individual lead-acid batteries. The active balancing device includes a switch driver chip, an energy storage unit, and a switch assembly corresponding to each of the individual lead-acid batteries. The energy storage unit includes a capacitor, an inductor, and a transformer.

[0048] After calculating the voltage difference between the maximum and minimum current voltages, the main controller determines whether the voltage difference is greater than a first preset voltage difference. If the voltage difference is not greater than the first preset voltage difference, the lead-acid battery pack is charged normally. If the voltage difference is greater than the first preset voltage difference, the main controller can send a conduction control signal to the switch driver chip to activate the switching component of the individual lead-acid battery corresponding to the maximum current voltage. The switch driver chip then controls the switching component of the individual lead-acid battery corresponding to the maximum current voltage to conduct based on the conduction control signal, thereby charging the active equalization device.

[0049] After the lead-acid battery corresponding to the maximum current voltage has been charged by the active balancing device for a preset period of time, the main controller can send a disconnect control signal to disconnect the switching component of the lead-acid battery corresponding to the maximum current voltage and a conduction control signal to turn on the switching component of the lead-acid battery corresponding to the minimum current voltage to the switch driver chip. The switch driver chip controls the switching component of the lead-acid battery corresponding to the maximum current voltage to disconnect based on the disconnect control signal and controls the switching component of the lead-acid battery corresponding to the minimum current voltage to turn on based on the conduction control signal, so as to charge the lead-acid battery corresponding to the minimum current voltage. After the active balancing device has charged the lead-acid battery corresponding to the minimum current voltage for a preset period of time, the above operation is repeated until the voltage difference between the maximum current voltage and the minimum current voltage is less than the first preset voltage difference.

[0050] In this embodiment, direct energy transfer is achieved through a bidirectional path: the lead-acid battery with the highest current voltage → active balancing device → active balancing device → lead-acid battery with the lowest current voltage, eliminating the energy waste of resistive passive balancing. Simultaneously, the active balancing device is connected in parallel with each lead-acid battery and is equipped with a switching component corresponding to each individual battery. The main controller can precisely activate the switching component of the lead-acid battery with the highest current voltage via a switch driver chip, ensuring that the energy storage unit of the active balancing device only receives energy from the lead-acid battery with the highest current voltage. Similarly, by activating the switching component of the lead-acid battery with the lowest current voltage, the charging unit releases energy only to the lead-acid battery with the lowest current voltage. Compared to the indiscriminate energy distribution or efficiency losses caused by multiple batteries participating in balancing simultaneously in traditional balancing schemes, the targeted balancing in this embodiment can quickly reduce the voltage difference between the lead-acid batteries with the highest and lowest current voltages, stabilizing it within a first preset voltage difference. This reduces irreversible damage to the batteries, such as internal resistance differentiation, capacity decay, undercharging sulfation, and overcharging bulging.

[0051] It is worth mentioning that this embodiment performs energy balancing processing for the entire charging process of the lead-acid battery pack. Therefore, after the voltage difference between the current voltage and the minimum current voltage is less than the first preset voltage difference, further, as an optional implementation, refer to... Figure 4 As shown, Figure 4 A flowchart illustrating the equalization process during the charging of a lead-acid battery pack includes the following steps after step S140: In step S410, the new current voltage of each individual lead-acid battery in the lead-acid battery pack is obtained.

[0052] In step S420, a new voltage difference is determined using the new maximum current voltage and the new minimum current voltage from the new current voltage.

[0053] In step S430, when the new voltage difference is greater than the first preset voltage difference, the active balancing device is used to reduce the voltage difference between the single lead-acid battery corresponding to the new maximum current voltage and the single lead-acid battery corresponding to the new minimum current voltage until the lead-acid battery pack finishes charging.

[0054] Specifically, after the voltage difference between the lead-acid cell with the maximum current voltage and the lead-acid cell with the minimum current voltage is reduced to below a first preset voltage difference using an active balancing device, the voltage acquisition module can acquire the new current voltage of each lead-acid cell. A new voltage difference is determined using the new maximum and new minimum current voltages. If the new voltage difference is greater than the first preset voltage difference, the aforementioned operation can be repeated to use the active balancing device to reduce the voltage difference between the lead-acid cell with the new maximum current voltage and the other lead-acid cells with the new minimum current voltage, until the lead-acid battery pack finishes charging.

[0055] Alternatively, as another optional implementation, during the process of reducing the voltage difference between the lead-acid battery with the maximum current voltage and the lead-acid battery with the minimum current voltage using an active balancing device, the main controller can collect the new current voltage of each lead-acid battery at a frequency of 100Hz using a voltage acquisition device, and determine the new maximum current voltage and the new minimum current voltage from the new current voltage. If the voltage difference between the new maximum current voltage and the new minimum current voltage is greater than a first preset voltage difference, the source lead-acid battery and the target lead-acid battery for energy transfer are dynamically switched, that is, the lead-acid battery with the new maximum current voltage is used as the source lead-acid battery, and the lead-acid battery with the new minimum current voltage is used as the target lead-acid battery. The active balancing device is used to balance and reduce the voltage difference between the lead-acid batteries with the new maximum current voltage and the lead-acid batteries with the new minimum current voltage until the lead-acid battery pack finishes charging.

[0056] In this embodiment, the method is not limited to single voltage difference detection and equalization. Instead, throughout the entire charging process of the lead-acid battery pack, a voltage acquisition device continuously acquires the new current voltage of each individual lead-acid battery at a preset frequency. Based on the new current voltage, the device locks the individual lead-acid battery with the new maximum current voltage and the new minimum current voltage in real time. By using an active equalization device to directionally reduce the voltage difference between the two, the device can accurately address the problem of dynamic voltage fluctuations and repeated voltage differences in individual lead-acid batteries during charging. In other words, through dynamic intervention throughout the entire process, the voltage difference between the individual lead-acid batteries in the battery pack is stably controlled within a first preset voltage difference. This can effectively suppress the rate of differentiation in the internal resistance and capacity of individual lead-acid batteries, thereby preventing the voltage difference from expanding again after a single equalization, which could lead to overcharging and water loss and bulging of some individual lead-acid batteries, or undercharging and sulfation, thus ensuring the charging safety of individual lead-acid batteries.

[0057] During the charging process of a lead-acid battery pack, when the voltage difference is greater than the first preset voltage difference but less than the second preset voltage difference, the voltage difference can be reduced by the active balancing device without taking other measures. However, when the voltage difference is greater than the second preset voltage difference but less than the third preset voltage difference, the voltage difference is already showing an increasing trend. The active balancing device alone may not be able to reduce the voltage difference between the lead-acid cells with the highest current voltage and the lowest current voltage. In this case, the charging current of the lead-acid battery pack can be reduced to reduce the voltage difference between the lead-acid cells with the highest and lowest current voltages. Accordingly, after reducing the charging current of the lead-acid battery pack to the preset charging current and charging the lead-acid battery pack for a preset time with the preset charging current, if the voltage difference is still greater than the third preset voltage difference, in order to avoid the lead-acid cells with the highest current voltage approaching the overcharge gas evolution threshold or the lead-acid cells with the lowest current voltage approaching the undercharge sulfation threshold due to continued charging, the charging circuit is disconnected and the charging of the lead-acid batteries is stopped. That is, as another optional real-time method, after step S120, the method further includes: if the voltage difference is greater than a second preset voltage difference, reducing the charging current by a preset charging current; wherein the second preset voltage difference is greater than the first preset low voltage difference. If the voltage difference is greater than a third preset voltage difference, reducing the charging current by a preset charging current; wherein the third preset voltage difference is greater than the second preset voltage difference; after charging the lead-acid battery pack for a preset time using the preset charging current, if the voltage difference between the maximum current voltage and the minimum current voltage is still greater than the third preset voltage difference, then charging the lead-acid battery pack is stopped.

[0058] In this embodiment, during the charging process of the lead-acid battery pack, the current voltage of each individual lead-acid battery is acquired, and the individual lead-acid battery with the maximum current voltage and the individual lead-acid battery with the minimum current voltage are locked. For the individual lead-acid batteries with the maximum current voltage and the individual lead-acid batteries with the minimum current voltage, the active balancing device is used as an energy transfer carrier to perform targeted energy transfer only on the extreme value individual lead-acid batteries, so as to reduce the voltage difference between individual lead-acid batteries. This can prevent some individual lead-acid batteries from overcharging and causing water loss and bulging, or undercharging and causing sulfation, thereby effectively eliminating the safety hazards of individual lead-acid battery bulging, electrolyte leakage, or even explosion, and thus significantly improving the reliability of the lead-acid battery of the liquid supply vehicle during the charging process.

[0059] To better understand this solution, a specific example is provided below.

[0060] The battery system includes a main controller, which is electrically connected to a voltage acquisition device, an active balancing device, a charging power device, a protection device, and an alarm device. The voltage acquisition device is connected via leads to the positive and negative terminals of each individual lead-acid battery in a lead-acid battery pack consisting of four 12V individual lead-acid batteries connected in series. The lead-acid battery pack includes individual lead-acid batteries B1, B2, B3, and B4. The active balancing device is also connected in parallel with each individual lead-acid battery to achieve bidirectional energy regulation.

[0061] See Figure 5 As shown, Figure 5 This is a schematic flowchart illustrating the battery charging method of this embodiment for the battery system.

[0062] The charging power device connects to the mains power supply and the lead-acid battery pack to charge the individual lead-acid batteries in the pack. After charging begins, the main controller uses a voltage acquisition device to collect the current voltage of batteries B1-B4 at a frequency of 100Hz. Assume the current voltage of B1 is 12.50V, B2 is 12.55V, B3 is 12.48V, and B4 is 12.62V.

[0063] The main controller identifies the maximum current voltage as 12.62V and the minimum current voltage as 12.48V from the current voltage, and calculates the voltage difference ΔVmax = 12.62V - 12.48V = 0.14V (140mV). Assume the first preset voltage difference T1 = 20mV, the second preset voltage difference T2 = 50mV, and the third preset voltage difference T3 = 100mV.

[0064] In this scenario, if the calculated voltage difference ΔVmax > T3, the charging current can be reduced to a preset charging current using the lead-acid battery pack's charging power device. The lead-acid battery pack can then be charged for a preset duration using this preset charging current. After the preset charging duration ends, if ΔVmax > T3, the charging circuit can be disconnected via a protection device to terminate charging, and an alarm message can be output via an alarm device. Alternatively, as another optional implementation, when ΔVmax > T3, the charging circuit can be directly disconnected via a protection device to terminate charging, and an alarm message can be output via an alarm device.

[0065] In another scenario, when ΔVmax < T3, first determine if the lead-acid battery pack is fully charged. If it is not fully charged and ΔVmax > T2, the charging current of the lead-acid battery pack can be reduced to a preset charging current, and the alarm device can be controlled to issue an alarm, i.e., reduce the charging current and trigger a primary alarm. After reducing the charging current, in order to minimize the voltage difference between the lead-acid battery with the highest current voltage and the lead-acid battery with the lowest current voltage as quickly as possible, the main control equalization device can also transfer the electrical energy of the lead-acid battery with the highest current voltage to the lead-acid battery with the lowest current voltage, i.e., activate active equalization, dynamically equalizing the energy transfer from the highest voltage cell to the lowest voltage cell.

[0066] Correspondingly, when T1 < ΔVmax < T2, the energy of the lead-acid battery with the highest current voltage can be transferred to the lead-acid battery with the lowest current voltage through the main control equalization device, that is, active equalization is started, and the energy transfer is dynamically balanced from the highest voltage cell to the lowest voltage cell.

[0067] After the active balancing and dynamic balancing of energy transfer from the highest-pressure cell to the lowest-pressure cell are initiated, the new current voltage of each lead-acid cell can be collected in real time at a preset frequency by a voltage acquisition device, and the voltage difference can be calculated from the new current voltage, that is, the cell voltage ΔVmax can be obtained in real time by acquisition and calculation.

[0068] Under the combined effects of equalization and current reduction, the voltages of the individual lead-acid batteries gradually become consistent, for example, becoming [12.53V, 12.54V, 12.53V, 12.55V], with ΔVmax = 20mV. At this point, the system removes the current limit, resumes normal charging, and continues fine equalization until the lead-acid battery pack is fully charged, at which point charging ends.

[0069] Thirdly, this embodiment provides a master controller, referring to... Figure 6 As shown, Figure 6 The diagram shows the structure of the main controller, which includes: One or more processors 101; The memory 102 stores one or more computer programs that, when executed by the one or more processors 101, cause the one or more processors 101 to implement the battery charging method according to the second aspect of the invention.

[0070] The main controller may also include one or more I / O interfaces 103 connected between the processor 101 and the memory 102, configured to enable information interaction between the processor 101 and the memory 102.

[0071] The processor 101 is a device with data processing capabilities, including but not limited to a central processing unit (CPU); the first memory is a device with data storage capabilities, including but not limited to random access memory (RAM, more specifically SDRAM, DDR, etc.), read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), and flash memory (FLASH); the I / O interface 103 (read-write interface) is connected between the processor 101 and the memory 102, enabling information exchange between the processor 101 and the memory 102, including but not limited to a data bus 104 (Bus).

[0072] In some embodiments, the processor 101, memory 102, and I / O interface 103 are interconnected via bus 104, and thus connected to other components of the computing device.

[0073] The above are merely specific embodiments of the present invention, but the scope of protection of the present invention is not limited thereto. Those skilled in the art should understand that the present invention includes, but is not limited to, the contents described in the accompanying drawings and the specific embodiments above. Any modifications that do not depart from the functional and structural principles of the present invention will be included within the scope of the claims.

Claims

1. A battery charging method applied to a host controller, characterized in that, The method comprises: acquiring current voltages of each single lead-acid battery in a lead-acid battery pack; determining a voltage difference value by using a maximum current voltage and a minimum current voltage in the current voltages; in a case where the voltage difference value is greater than a first preset voltage difference value, controlling the single lead-acid battery corresponding to the maximum current voltage to charge an active balancing device; wherein the active balancing device is an energy regulating device for balancing voltage differences between single lead-acid batteries in the lead-acid battery pack; after charging the active balancing device for a preset time length, controlling the active balancing device to charge the single lead-acid battery corresponding to the minimum current voltage until the voltage difference value between the maximum current voltage and the minimum current voltage is less than the first preset voltage difference value.

2. The battery charging method according to claim 1, wherein, The active balancing device is connected in parallel with each single lead-acid battery, and the active balancing device comprises a switch driving chip, an energy storage unit, and a switch assembly corresponding to each single lead-acid battery. After charging the active balancing device for a preset time length, the step of controlling the active balancing device to charge the single lead-acid battery corresponding to the minimum current voltage until the voltage difference value between the maximum current voltage and the minimum current voltage is less than the first preset voltage difference value comprises: sending a conduction control signal to the switch driving chip to make the switch driving chip turn on the switch assembly of the single lead-acid battery corresponding to the maximum current voltage based on the conduction control signal, and charge the energy storage unit; after charging the active balancing device for a preset time length, sending a conduction control signal to the switch driving chip to make the switch driving chip turn on the switch assembly of the single lead-acid battery corresponding to the minimum current voltage based on the conduction control signal, and charge the single lead-acid battery corresponding to the minimum current voltage.

3. The battery charging method according to claim 2, wherein The energy storage unit comprises a capacitor, an inductor, and a transformer.

4. The battery charging method of claim 1, wherein, After charging the active balancing device for a preset time length and controlling the active balancing device to charge the single lead-acid battery corresponding to the minimum current voltage until the voltage difference value between the maximum current voltage and the minimum current voltage is less than the first preset voltage difference value, the method further comprises: acquiring new current voltages of each single lead-acid battery in the lead-acid battery pack; determining a new voltage difference value by using a new maximum current voltage and a new minimum current voltage in the new current voltages; in a case where the new voltage difference value is greater than the first preset voltage difference value, reducing the voltage difference value between the single lead-acid battery corresponding to the new maximum current voltage and the single lead-acid battery corresponding to the new minimum current voltage by using the active balancing device until the lead-acid battery pack ends charging.

5. The battery charging method of claim 1, wherein, After determining the voltage difference value by using the maximum current voltage and the minimum current voltage in the current voltages, the method further comprises: in a case where the voltage difference value is greater than a second preset voltage difference value, reducing a preset charging current by a charging current reduction value; wherein the second preset voltage difference value is greater than the first preset low voltage difference value.

6. The battery charging method according to claim 5, wherein The method further comprises, after determining the voltage difference value using the maximum current voltage and the minimum current voltage in the current voltage: In a case where the voltage difference value is greater than the third preset voltage difference value, the preset charging current is a charging current reduction value; wherein the third preset voltage difference value is greater than the second preset voltage difference value; After charging the lead-acid battery group for a preset time period using the preset charging current, if the voltage difference value between the maximum current voltage and the minimum current voltage is still greater than the third preset voltage difference value, the charging of the lead-acid battery group is stopped.

7. A master controller, comprising: The method comprises: one or more processors; a memory having one or more computer programs stored thereon, wherein when the one or more computer programs are executed by the one or more processors, the one or more processors implement the battery charging method according to any one of claims 1 to 6.

8. A battery system characterized by, The battery system comprises a lead-acid battery group, a master controller, a voltage acquisition device, and an active balancing device, the lead-acid battery group comprises a plurality of single lead-acid batteries connected in series, the voltage acquisition device and the active balancing device are connected in parallel with the single lead-acid batteries respectively, and the master controller is connected with the active balancing device and the voltage acquisition device respectively, The voltage acquisition device acquires the current voltage of each single lead-acid battery under the control of the master controller; The active balancing device reduces the voltage difference between the single lead-acid batteries under the control of the master controller; The master controller is the master controller of claim 7.

9. The battery system of claim 8, wherein, The battery system further comprises a charging power device and a protection device, the charging power device is connected with the controller, the lead-acid battery group, and the commercial power supply respectively, and the protection device is connected with the master controller and the charging power device respectively, The charging power device reduces the charging current to a preset charging current under the control of the master controller; The protection device disconnects the charging circuit of the lead-acid battery group under the control of the master controller.

10. The battery system of claim 8, wherein, The battery system further comprises an alarm device, and the alarm device is connected with the master controller, The alarm device outputs alarm information under the control of the master controller.

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