Lead-acid battery active equalization method and device

Abstract

The invention discloses a lead-acid battery active equalization method and device, which are applied to a to-be-controlled battery pack comprising a plurality of lead-acid batteries connected in series, the to-be-controlled battery pack is used for charging a load, and the method comprises the following steps: collecting the working state of the to-be-controlled battery pack and the battery voltage corresponding to the lead-acid batteries; determining an equalization type corresponding to the lead-acid battery according to the battery voltage; and according to the working state and the equalization type, carrying out electric quantity equalization on the plurality of lead-acid batteries in the to-be-controlled battery pack. The voltage of each single lead-acid battery is collected, the equalization type of each single lead-acid battery is determined, and the current working state of the to-be-controlled battery pack is combined to realize electric quantity equalization of the plurality of lead-acid batteries in the to-be-controlled battery pack, so that the performance degradation of the battery pack is effectively delayed, and the overall cycle life is greatly prolonged.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of battery equalization, in particular to a lead-acid battery active equalization method and device. BACKGROUND

[0002] At present, based on the advantages of high safety factor and low cost of lead-acid batteries, most domestic two-wheeled electric vehicles use power lead-acid battery packs as power sources. With the gradual improvement of users' requirements for vehicle performance, the number of batteries in series in the power lead-acid battery pack is also increasing. When leaving the factory, the internal resistance, voltage and other characteristics of each power lead-acid battery cannot be exactly the same. If the voltage difference of individual lead-acid batteries is not controlled, the difference will become larger and larger with the increase of the number of uses. This means that the more the number of lead-acid batteries in series, the faster the difference rate, and the shorter the life of the battery pack.

[0003] However, due to the low energy density and large volume of lead-acid batteries, and the limited space of two-wheeled electric vehicles, the lead-acid battery pack cannot form a closed battery pack like a lithium battery, and a BMS (Battery Management System) is added inside the battery pack to monitor and protect each lead-acid battery, such as active equalization or passive equalization, to keep the voltage of each lead-acid battery consistent.

[0004] Therefore, there is an urgent need for a lead-acid battery active equalization method that can equalize the voltage of each lead-acid battery in the battery pack. SUMMARY

[0005] In order to overcome the shortcomings of the prior art, the purpose of the present application is to provide a lead-acid battery active equalization method and device which can equalize the power of multiple lead-acid batteries in series in the battery to be controlled.

[0006] In order to solve the above problems, the present application is realized according to the following scheme:

[0007] A lead-acid battery active equalization method is provided, applied to a battery to be controlled including multiple lead-acid batteries in series, the battery to be controlled being used to discharge to a load, comprising:

[0008] Collecting the working state of the battery to be controlled and the battery voltage corresponding to the lead-acid battery;

[0009] According to the battery voltage, determining the equalization type corresponding to the lead-acid battery;

[0010] According to the working state and the equalization type, the power of the multiple lead-acid batteries in the battery to be controlled is equalized.

[0011] Compared with the prior art, the lead-acid battery active balancing method has the following beneficial effects: by collecting the voltages of the single lead-acid batteries and determining the balancing types thereof, and in combination with the current working state of the battery pack to be controlled, the electric quantity of the plurality of lead-acid batteries in the battery pack to be controlled is balanced, so that the performance degradation of the battery pack is effectively delayed, and the overall cycle life is greatly prolonged.

[0012] Optionally, the balancing type corresponding to the lead-acid battery is determined according to the battery voltage, and the balancing type corresponding to the lead-acid battery includes:

[0013] The average voltage of the plurality of lead-acid batteries is determined according to the battery voltage.

[0014] When the battery voltage of the lead-acid battery is greater than the average voltage, the balancing type corresponding to the lead-acid battery is top balancing.

[0015] When the battery voltage of the lead-acid battery is less than the average voltage, the balancing type corresponding to the lead-acid battery is bottom balancing.

[0016] Optionally, the lead-acid battery is connected in parallel with a flyback transformer.

[0017] When the working state is a discharging state, the electric quantity of the plurality of lead-acid batteries in the battery pack to be controlled is balanced according to the working state and the balancing type, and the balancing includes:

[0018] The battery electric quantity of the lead-acid battery is determined according to the battery voltage.

[0019] The target battery in the battery pack to be controlled is determined according to the balancing type and the battery electric quantity.

[0020] When the balancing type is top balancing, the lead-acid battery with a battery electric quantity greater than a preset electric quantity is determined as the target battery, the primary coil of the flyback transformer stores the electric quantity released by the target battery to the secondary coil of the flyback transformer, when the time for the target battery to release the electric quantity is equal to a preset time, the primary coil of the flyback transformer discharges the electric quantity released by the target battery and the battery pack to be controlled to the load at the same time, so as to transfer the excess electric quantity of the target battery to the load, the battery voltage of the lead-acid battery is collected again, the average voltage of the plurality of lead-acid batteries is determined, and the above processes of electric quantity transfer and average voltage determination are repeated until the difference between the battery voltage of the target battery and the average voltage is less than or equal to a preset voltage, and the target battery stops releasing the electric quantity.

[0021] When the balancing type is bottom balancing, a lead-acid battery with a battery charge less than a preset charge is determined as the target battery, and the primary coil of the flyback transformer stores the charge released by the battery group to be controlled to the secondary coil of the flyback transformer. When the time for the lead-acid batteries in the battery group to be controlled to release the charge is equal to the preset time, the primary coil of the flyback transformer transfers the charge released by the battery group to be controlled to the secondary coil connected in parallel with the target battery. The target battery and the secondary coil connected in parallel with the target battery simultaneously discharge the load to transfer the excess charge of the battery group to be controlled to the load. The battery voltage of the lead-acid battery is collected again to determine the average voltage of the multiple lead-acid batteries. The above-mentioned charge transfer and average voltage determination process is repeated until the difference between the battery voltage of any lead-acid battery in the battery group to be controlled and the average voltage is less than or equal to the preset voltage, and the battery group to be controlled stops releasing charge.

[0022] Optionally, the lead-acid battery is connected in parallel with a flyback transformer;

[0023] When the working state is a static state, performing power balancing on the plurality of lead-acid batteries in the battery group to be controlled according to the working state and the balancing type includes:

[0024] determining the battery capacity of the lead-acid battery according to the battery voltage;

[0025] Determining a target battery in the battery group to be controlled according to the balancing type and the battery power;

[0026] When the balancing type is top balancing, a lead-acid battery with a battery charge greater than a preset charge is determined as the target battery, the primary coil of the flyback transformer stores the charge released by the target battery to the secondary coil of the flyback transformer, and when the time for the target battery to release charge equals the preset time, the primary coil of the flyback transformer uses the charge released by the target battery to charge the battery group to be controlled, so as to transfer excess energy of the target battery to each lead-acid battery, and the battery voltage of the lead-acid battery is collected again to determine the average voltage of the multiple lead-acid batteries, until the difference between the battery voltage of the target battery and the average voltage equals the preset voltage, at which point the target battery stops releasing charge;

[0027] When the equalization type is bottom equalization, the lead-acid battery with battery voltage less than the preset battery voltage is determined as the target battery, the primary coil of the flyback transformer stores the battery voltage released by the to-be-controlled battery group to the secondary coil of the flyback transformer, when the time for the lead-acid battery in the to-be-controlled battery group to release battery voltage is equal to the preset time, the primary coil of the flyback transformer transfers the battery voltage released by the to-be-controlled battery group to the secondary coil in parallel with the target battery, the target battery is charged through the secondary coil in parallel with the target battery to transfer the excess battery voltage of the to-be-controlled battery group to the target battery, the battery voltage of the lead-acid battery is collected again, the average voltage of the plurality of lead-acid batteries is determined, and the above battery voltage transfer and average voltage determination process is repeated until the difference between the battery voltage of any one of the lead-acid batteries in the to-be-controlled battery group and the average voltage is equal to the preset voltage, and the to-be-controlled battery group stops releasing battery voltage.

[0028] Optionally, the lead-acid battery is in parallel with the flyback transformer.

[0029] When the working state is the charging state, the lead-acid battery is connected with the charger, and the battery voltage equalization of the plurality of lead-acid batteries in the to-be-controlled battery group is performed according to the working state and the equalization type, including:

[0030] The battery voltage is used to determine the corresponding battery voltage of the lead-acid battery.

[0031] The target battery is determined in the to-be-controlled battery group according to the equalization type and the battery voltage.

[0032] When the equalization type is top equalization, the lead-acid battery with battery voltage greater than the preset battery voltage is determined as the target battery, the target battery current of the target battery charged by the charger is divided into a charging current for charging the target battery and a battery group equalization current, the primary coil of the flyback transformer stores the battery voltage supplemented by the battery group equalization current to the secondary coil of the flyback transformer, when the charging time of the secondary coil of the flyback transformer is equal to the preset time, the primary coil of the flyback transformer supplements the battery voltage of the to-be-controlled battery group with the battery voltage supplemented by the battery group equalization current to the secondary coil of the flyback transformer and the charger to transfer the part of the battery voltage supplemented to the target battery to each lead-acid battery, the battery voltage of the lead-acid battery is collected again, the average voltage of the plurality of lead-acid batteries is determined, and the above battery voltage transfer and average voltage determination process is repeated until the difference between the battery voltage of the target battery and the average voltage is equal to the preset voltage, and the battery voltage equalization of the plurality of lead-acid batteries in the to-be-controlled battery group is stopped.

[0033] When the balancing type is bottom balancing, a lead-acid battery with a battery charge less than a preset charge is determined as the target battery. The target battery group current used by the charger to charge the battery group to be controlled is divided into a charging current for the battery group to be controlled and a battery balancing current. The primary coil of the flyback transformer stores the charge supplied to the secondary coil of the flyback transformer by the battery balancing current. When the charging time of the secondary coil of the flyback transformer equals a preset time, the primary coil of the flyback transformer transfers the charge supplied to the secondary coil of the flyback transformer by the battery balancing current to the secondary coil connected in parallel with the target battery. The target battery is charged simultaneously by the secondary coil connected in parallel with the target battery and the charger, thereby transferring part of the charge supplied to the battery group to the target battery. The battery voltage of the lead-acid battery is again collected to determine the average voltage of the multiple lead-acid batteries. The above energy transfer and average voltage determination process is repeated until the difference between the battery voltage of any lead-acid battery in the battery group to be controlled and the average voltage equals the preset voltage, at which point energy balancing of the multiple lead-acid batteries in the battery group to be controlled is stopped.

[0034] A lead-acid battery active balancing device is also provided, which is applied to the above-mentioned lead-acid battery active balancing method, comprising: a control module, a switch module, a flyback transformer and a sampling module; the control module is connected to the switch module, the flyback transformer and the sampling module; the flyback transformer is connected to the lead-acid battery, the switch module and the sampling module; the lead-acid battery is connected to the switch module;

[0035] The sampling module generates a feedback signal including the working status and the battery voltage, the control module generates a control signal based on the feedback signal, and the switching module closes or closes the connection between the lead-acid battery and the flyback transformer based on the control signal to store the electricity discharged by the target battery or the battery pack to be controlled in the flyback transformer; the flyback transformer switches the connection between the charging and discharging states based on the control signal to transfer the electricity to the target battery or the battery pack to be controlled.

[0036] Optionally, the flyback transformer includes a primary coil and secondary coils having the same number as the lead-acid batteries; the primary coil is connected to the lead-acid battery, the sampling module, and the control module, and the secondary coil is connected to the switch module.

[0037] Optionally, the switch module includes a plurality of switch units with the same structure, and the number of the switch units is the same as the number of the lead-acid batteries; the switch units are connected to the lead-acid batteries, the control module, and the secondary coil.

[0038] Optionally, the switching unit includes a switching tube and a signal output circuit, the switching tube is connected to the lead-acid battery and the signal output circuit, and the signal output circuit is connected to the secondary coil.

[0039] Optionally, the control module includes a processor and a memory, the memory storing at least one instruction, at least one program, code set or instruction set, and the at least one instruction, at least one program, code set or instruction set is loaded and executed by the processor to implement the active balancing method for lead-acid batteries. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] Figure 1 is a flow chart of the active balancing method of the present invention;

[0041] Figure 2 This is a structural block diagram of the active equalization device of the present invention;

[0042] Figure 3 is a schematic diagram of a signal amplifying circuit of the present invention;

[0043] Figure 4 A partial circuit diagram of the active equalization device of the present invention;

[0044] Figure 5 Schematic diagram of the control chip of the present invention;

[0045] Description of the accompanying drawings: 1. control module; 101. control chip; 102. signal amplification circuit; 103. transformer control unit; 2. switch module; 201. switch tube; 202. signal output circuit; 3. flyback transformer; 4. sampling module; 5. battery pack to be controlled; DETAILED DESCRIPTION

[0046] The preferred embodiments of the present invention are described below with reference to the accompanying drawings. It should be understood that the preferred embodiments described herein are only used to illustrate and explain the present invention, and are not used to limit the present invention.

[0047] When the following description refers to the accompanying drawings, unless otherwise indicated, the same numbers in different drawings represent the same or similar elements. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with the present application. On the contrary, they are merely examples of devices and methods consistent with some aspects of the present application as detailed in the appended claims. In the description of the present application, it should be understood that the terms "first", "second", "third", etc. are only used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence, nor can they be understood as indicating or implying relative importance. For those of ordinary skill in the art, the specific meanings of the above terms in the present application can be understood according to the specific circumstances.

[0048] See alsoFigure 1 As shown, the lead-acid battery active balancing method of the present application is applied to a to-be-controlled battery pack including a plurality of series-connected lead-acid batteries, and the to-be-controlled battery pack is used to discharge to a load, and comprises:

[0049] S1: Collect the working state of the to-be-controlled battery pack and the battery voltage corresponding to the lead-acid battery; wherein the working state includes a state for indicating that the to-be-controlled battery pack discharges to a load, a static state for indicating that the to-be-controlled battery pack is not in charging or discharging, and a charging state for indicating that the to-be-controlled battery pack stores power, and the working state of the to-be-controlled battery pack is determined by collecting the current flow direction, when the current flow direction is from the to-be-controlled battery pack to the load, it is the discharging state, when the current flow direction is from the outside to the to-be-controlled battery pack, it is the charging state, and when there is no current, it is the static state.

[0050] The output voltage of the to-be-controlled battery pack as a whole only reflects the sum of the battery voltages of the series-connected batteries, and it cannot reflect the voltage difference of each lead-acid battery in the battery pack (for example, when a lead-acid battery is overcharged / under-voltage, the total voltage of the battery pack may still be normal), and the battery voltage of the lead-acid battery is used to determine the balancing state and SOC (state of charge) difference of the single lead-acid battery, and only by collecting the battery voltage of the single lead-acid battery can the power balance between the plurality of lead-acid batteries be accurately identified, and the corresponding balancing measures can be performed, thereby avoiding the decline of the overall performance of the battery pack due to the imbalance of the power between the lead-acid batteries.

[0051] S2: According to the battery voltage, determine the balancing type corresponding to the lead-acid battery, comprising: according to the battery voltage, determine the average voltage of the plurality of lead-acid batteries; according to the battery voltage and the average voltage, determine the balancing type, specifically:

[0052] When the battery voltage of the lead-acid battery is greater than the average voltage, it indicates that the state of charge (SOC) of the lead-acid battery is higher than that of other lead-acid batteries in the battery pack, and there is a risk of overcharging or it has been in a relatively full state, and the balancing type corresponding to the lead-acid battery is top balancing, at this time, the excess power of the lead-acid battery is released to reduce the battery voltage of the lead-acid battery to the average level, thereby avoiding damage to the lead-acid battery due to excessive voltage, and balancing the overall SOC of the battery pack and improving the overall performance and life of the battery pack.

[0053] When the battery voltage of the lead-acid battery is less than the average voltage, it indicates that the state of charge (SOC) of the lead-acid battery is lower than that of other lead-acid batteries in the battery pack, and there is a risk of under-voltage or capacity decay, and the balancing type corresponding to the lead-acid battery is bottom balancing, at this time, the power of the lead-acid battery is supplemented alone (such as increasing the charging power of the lead-acid battery during charging), to improve the battery voltage to the average level, thereby avoiding the accelerated performance degradation of the lead-acid battery due to long-term under-voltage, thereby balancing the overall SOC of the battery pack and restoring the consistency and overall endurance of the battery pack.

[0054] S3: performing charge balancing on multiple lead-acid batteries in the battery group to be controlled according to the working state and the balancing type, wherein the lead-acid batteries are connected in parallel with the flyback transformer.

[0055] In one embodiment of the present invention, when the working state is the discharge state and the balancing type is top balancing, charge balancing is performed on multiple lead-acid batteries in the battery group to be controlled according to the working state and the balancing type, including: first, determining the battery charge corresponding to the lead-acid battery according to the battery voltage; then, determining a target battery in the battery group to be controlled according to the balancing type and the battery charge, specifically, determining a lead-acid battery with a battery charge greater than a preset charge as the target battery; finally, storing the charge released by the target battery to the secondary coil of the flyback transformer in the primary coil of the flyback transformer; when the time for the target battery to release the charge is equal to the preset time, the primary coil of the flyback transformer uses the charge released by the target battery and the battery group to be controlled to discharge the load simultaneously to transfer the excess charge of the target battery to the load, and then collecting the battery voltage of the lead-acid battery again to determine the average voltage of the multiple lead-acid batteries. The above charge transfer and average voltage determination process is repeated until the difference between the battery voltage of the target battery and the average voltage is less than or equal to the preset voltage, and the target battery stops releasing the charge.

[0056] In one embodiment of the present invention, when the working state is the discharge state and the balancing type is the bottom balancing, the power balancing is performed on multiple lead-acid batteries in the battery group to be controlled according to the working state and the balancing type, including: first, determining the battery power corresponding to the lead-acid battery according to the battery voltage; then, determining the target battery in the battery group to be controlled according to the balancing type and the battery power, specifically, determining the lead-acid battery with a battery power less than a preset power as the target battery; finally, the primary coil of the flyback transformer stores the power released by the battery group to be controlled to the secondary coil of the flyback transformer, and when the battery group to be controlled When the time for the lead-acid battery to release electricity is equal to the preset time, the primary coil of the flyback transformer transfers the electricity released by the battery group to be controlled to the secondary coil connected in parallel with the target battery. The target battery and the secondary coil connected in parallel with it discharge the load at the same time to transfer the excess electricity of the battery group to be controlled to the load. The battery voltage of the lead-acid battery is collected again, and the average voltage of the multiple lead-acid batteries is determined. The above-mentioned electricity transfer and average voltage determination process is repeated until the difference between the battery voltage of any lead-acid battery in the battery group to be controlled and the average voltage is less than or equal to the preset voltage, and the battery group to be controlled stops releasing electricity.

[0057] In one embodiment of the present application, when the working state is the static state and the equalization type is the top equalization, the battery power of the plurality of lead-acid batteries in the battery group to be controlled is equalized according to the working state and the equalization type, which includes: first, determining the battery power of the lead-acid battery corresponding to the battery voltage; then, determining the target battery in the battery group to be controlled according to the equalization type and the battery power, specifically, the lead-acid battery with the battery power greater than the preset power is determined as the target battery; finally, the primary coil of the flyback transformer stores the power released from the target battery to the secondary coil of the flyback transformer, when the time of the target battery releasing the power is equal to the preset time, the primary coil of the flyback transformer charges the plurality of lead-acid batteries in the battery group to be controlled with the power released from the target battery, so as to transfer the excess energy of the target battery to the plurality of lead-acid batteries, the battery voltage of the lead-acid battery is collected again, the average voltage of the plurality of lead-acid batteries is determined, until the difference between the battery voltage of the target battery and the average voltage is equal to the preset voltage, the target battery stops releasing the power.

[0058] In one embodiment of the present application, when the working state is the static state and the equalization type is the bottom equalization, the battery power of the plurality of lead-acid batteries in the battery group to be controlled is equalized according to the working state and the equalization type, which includes: first, determining the battery power of the lead-acid battery corresponding to the battery voltage; then, determining the target battery in the battery group to be controlled according to the equalization type and the battery power, specifically, the lead-acid battery with the battery power less than the preset power is determined as the target battery; finally, the primary coil of the flyback transformer stores the power released from the battery group to be controlled to the secondary coil of the flyback transformer, when the time of the lead-acid battery in the battery group to be controlled releasing the power is equal to the preset time, the primary coil of the flyback transformer transfers the power released from the battery group to be controlled to the secondary coil parallel to the target battery, charges the target battery through the secondary coil parallel to the target battery, so as to transfer the excess power of the battery group to be controlled to the target battery, the battery voltage of the lead-acid battery is collected again, the average voltage of the plurality of lead-acid batteries is determined, the above power transfer and average voltage determination process is repeated until the difference between the battery voltage of any one of the lead-acid batteries in the battery group to be controlled and the average voltage is equal to the preset voltage, the battery group to be controlled stops releasing the power.

[0059] In one embodiment of the present application, when the working state is the charging state and the equalization type is the top equalization, the lead-acid batteries are connected with the charger, and the electric quantity of the plurality of lead-acid batteries in the controlled battery group is equalized according to the working state and the equalization type, including: first, the battery voltage is used to determine the corresponding battery electric quantity of the lead-acid battery; then, the equalization type and the battery electric quantity are used to determine the target battery in the controlled battery group, specifically, the lead-acid battery with the battery electric quantity greater than the preset electric quantity is determined as the target battery; finally, the target battery current of the charger charging the target battery is divided into the charging current for charging the target battery and the battery group equalization current, the primary coil of the flyback transformer stores the electric quantity supplemented by the battery group equalization current to the secondary coil of the flyback transformer, when the charging time of the secondary coil of the flyback transformer is equal to the preset time, the primary coil of the flyback transformer uses the electric quantity supplemented by the battery group equalization current to the secondary coil of the flyback transformer and the charger to charge the plurality of lead-acid batteries in the controlled battery group at the same time, so as to transfer the part of the electric quantity supplemented to the target battery to each lead-acid battery, the battery voltage of the lead-acid battery is collected again, the average voltage of the plurality of lead-acid batteries is determined, the above electric quantity transfer and average voltage determination process is repeated until the difference between the battery voltage of the target battery and the average voltage is equal to the preset voltage, and the electric quantity equalization of the plurality of lead-acid batteries in the controlled battery group is stopped.

[0060] In one embodiment of the present application, when the working state is the charging state and the equalization type is the bottom equalization, the electric quantity of the plurality of lead-acid batteries in the controlled battery group is equalized according to the working state and the equalization type, including: first, the battery voltage is used to determine the corresponding battery electric quantity of the lead-acid battery; then, the equalization type and the battery electric quantity are used to determine the target battery in the controlled battery group, specifically, the lead-acid battery with the battery electric quantity less than the preset electric quantity is determined as the target battery; finally, the target battery group current of the charger charging the controlled battery group is divided into the charging current for charging the controlled battery group and the battery equalization current, the primary coil of the flyback transformer stores the electric quantity supplemented by the battery equalization current to the secondary coil of the flyback transformer, when the charging time of the secondary coil of the flyback transformer is equal to the preset time, the primary coil of the flyback transformer transfers the electric quantity supplemented by the battery equalization current to the secondary coil of the flyback transformer to the secondary coil parallel to the target battery, the target battery is charged by the secondary coil parallel to the target battery and the charger at the same time, so as to transfer the part of the electric quantity supplemented to the controlled battery group to the target battery, the battery voltage of the lead-acid battery is collected again, the average voltage of the plurality of lead-acid batteries is determined, the above electric quantity transfer and average voltage determination process is repeated until the difference between the battery voltage of any one of the lead-acid batteries in the controlled battery group and the average voltage is equal to the preset voltage, and the electric quantity equalization of the plurality of lead-acid batteries in the controlled battery group is stopped.

[0061] The above preset time can be set according to actual needs and is not limited here.

[0062] See also Figure 2 As shown, a lead-acid battery active balancing device includes: a control module 1, a switch module 2, a flyback transformer 3 and a sampling module 4; the control module 1 is connected to the switch module 2, the flyback transformer 3 and the sampling module 4, and the flyback transformer 3 is connected to the lead-acid battery, the switch module 2 and the sampling module 4; the battery group 5 to be controlled includes multiple lead-acid batteries connected in series, and the lead-acid battery is connected to the control module 1 and the flyback transformer 3.

[0063] The sampling module 4 generates a feedback signal, the control module 1 generates a control signal according to the feedback signal, the switch module 2 closes or closes the connection between the lead-acid battery and the flyback transformer 3 according to the control signal, and the flyback transformer 3 switches the charge and discharge state according to the feedback signal.

[0064] In one embodiment of the present invention, the flyback transformer 3 includes a primary coil and secondary coils having the same number as the lead-acid batteries. Taking the resistor to be controlled formed by 6 lead-acid batteries commonly connected in series on the market as an example, there are 6 secondary coils in total and 2 primary coils. The turns ratio of the primary coil to the secondary coil is 3:1. The primary coil is connected to the lead-acid battery, the sampling module 4, and the control module 1. The first input end of the secondary coil is connected to the switch module 2, and the second input end of the secondary coil is connected to the lead-acid battery.

[0065] In one embodiment of the present invention, the switch module 2 includes multiple switch units with the same structure, and the number of the switch units is the same as the number of lead-acid batteries; each switch unit is connected to a lead-acid battery, the control module 1, and the first input end of the secondary coil; wherein the switch unit includes a switch tube 201 which is a MOS tube and a signal output circuit 202, the switch tube 201 is connected to the control module 1 and the signal output circuit 202, and the signal output circuit 202 is connected to the first input end of the secondary coil.

[0066] The control module 1 includes an STM32F103C8T6 control chip 101, a signal amplification circuit 102, and a transformer control unit 103. The control chip 101 is connected to the signal amplification circuit 102, the transformer control unit 103, and the sampling module 4. The signal amplification circuit 102 is connected to the switch 201, and the transformer control unit 103 is connected to the primary coil. The active balancing device of the present invention is described below using a battery pack 5 to be controlled, consisting of six lead-acid batteries connected in series, as an example.

[0067] See also Figures 3-5As shown, the negative electrode of the lead-acid battery is connected with the signal amplification circuit 102 to form a current loop of the lead-acid battery positive electrode-secondary coil first input-secondary coil second input-switching unit-signal amplification circuit 102-lead-acid battery negative electrode, the initial signal output by the control chip 101 is amplified by the signal amplification circuit 102 to obtain six control signals S1, S2,..., S6, which are used to control the switching state of the switching tube 201; when the signal amplification circuit 102 has no output, the lead-acid battery will not self-discharge or charge, so as to avoid self-consumption of the lead-acid battery when it is at rest and prolong the service life of the lead-acid battery.

[0068] When the switching tube 201 is opened, the connection between the switching tube 201 and the first input of the secondary coil is closed, at this time, the current loop of the switching tube 201-secondary coil first input-secondary coil second input-lead-acid battery is closed, that is, the lead-acid battery is connected (current loop) with the secondary coil of the flyback transformer 3, at this time, the lead-acid battery releases the electric quantity to the secondary coil, and when the switching tube 201 is closed, the primary coil stores the electric quantity released by the lead-acid battery due to the principle of mutual inductance.

[0069] The sampling module 4 feeds back the voltage of each lead-acid battery through the feedback signal Umux, so that only one I / O port of the control chip 101 can sample the voltage of the six lead-acid batteries, the transformer control unit 103 includes a MOS tube T7, and the control signal Prim_L generated by the control chip 101 is used to switch the charge and discharge state of the primary coil of the flyback transformer 3, specifically, the switching state of the MOS tube T7 is controlled, when the MOS tube T7 is closed, the flyback transformer 3 is in a charging state, and when the MOS tube T7 is opened, the flyback transformer 3 is in a discharging state. Specifically, when the MOS tube T7 is opened, the primary coil loop is turned on to charge the battery pack to be controlled or discharge to the load together with the battery pack to be controlled; or in the state that the MOS tube T7 remains closed, when any one of the switching tubes 201 changes from the closed state to the opened state, the secondary coil connected with the switching tube 201 is in the conducting state, and the primary coil releases the electric quantity to the secondary coil, at this time, the secondary coil charges the lead-acid battery connected in parallel therewith or discharges to the load together with the lead-acid battery.

[0070] In an embodiment of the present application, the control module includes a processor and a memory, the memory stores at least one instruction, at least one program, a code set or an instruction set, the at least one instruction, at least one program, code set or instruction set is loaded and executed by the processor to realize the active balancing method described above.

[0071] The processor can be a central processing unit (CPU), other general-purpose processors, digital signal processors (DSP), application-specific integrated circuits (ASIC), field-programmable gate arrays (FPGA) or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc.

[0072] The memory can be used to store the computer program or module, and the processor implements the various functions of the active balancing method by running or executing the computer program or module stored in the memory and calling the data stored in the memory. The memory can mainly include a program storage area and a data storage area, wherein the program storage area can store an operating system, at least one application required for a function, etc.; the data storage area can store data created based on the use of the mobile phone, etc. In addition, the memory can include a high-speed random access memory and can also include a non-volatile memory, such as a hard disk, a memory, a plug-in hard disk, a smart memory card (Smart Media Card, SMC), a secure digital (Secure Digital, SD) card, a flash card (Flash Card), at least one disk storage device, a flash memory device, or other volatile solid-state storage device.

[0073] Assuming that the preset voltage is 0.1V and the preset capacity is 50% of the rated capacity of the lead-acid battery pack, when the capacity of a single battery is greater than the preset capacity, its battery voltage is usually higher than the voltage of the remaining lead-acid batteries. This is because the internal chemical reaction of the battery with a higher capacity is more complete, the ion concentration is higher, and the electromotive force is higher. The following is a detailed description of the process of the active balancing method performed by the active balancing device of the present invention:

[0074] Assuming that the voltage of lead-acid battery B1 is higher than that of the other lead-acid batteries (the charge of lead-acid battery B1 is higher than the preset charge), lead-acid battery B1 is the target battery. At this time, the balancing type corresponding to lead-acid battery B1 is top balancing. At this time, when the working state of the battery group to be controlled is the discharge state, the balancing steps performed by the balancing device are:

[0075] The control chip 101 generates a control signal S1 to control the switch tube T8 to turn on, so that the lead-acid battery B1 releases electricity to the secondary coil connected in parallel with it. After the electricity release time reaches a preset time, the control signal S1 for turning off the switch tube T8 is generated. The flyback transformer 3 uses mutual inductance to transfer the electric energy of the secondary coil to the primary coil, that is, the primary coil stores the electricity released by the lead-acid battery B1 to the secondary coil. Then the control chip 101 generates a control signal Prim_L for turning on the MOS tube T7 (transformer control unit 103). At this time, the primary coil and the battery pack to be controlled jointly discharge to the load, so as to directly transfer the excess electricity of the lead-acid battery B1 to the primary coil. The battery is discharged to the load (excess power is transferred to the load), and the battery voltages of all lead-acid batteries are collected again to determine the difference between the voltage of lead-acid battery B1 and the average voltage of all lead-acid batteries. The above power transfer and average voltage determination process is repeated until the difference between the voltage of lead-acid battery B1 and the average voltage of all lead-acid batteries is no more than 0.1V. The balancing step is then stopped to transfer the excess power of lead-acid battery B1 to the load through the mutual inductance of the flyback transformer 3. While balancing the voltage of lead-acid battery B1 with the voltages of the remaining lead-acid batteries, the primary coil and the battery group to be controlled are discharged to the load together, thereby achieving power balancing of multiple lead-acid batteries in the battery group.

[0076] Assuming that the voltage of lead-acid battery B1 is higher than that of the other lead-acid batteries (the charge of lead-acid battery B1 is higher than the preset charge), lead-acid battery B1 is the target battery. At this time, the balancing type corresponding to lead-acid battery B1 is top balancing. At this time, when the working state of the battery pack to be controlled is the static state, the balancing steps performed by the balancing device are:

[0077] The control chip 101 generates a control signal S1 to control the switch tube T8 to open, so that the lead-acid battery B1 releases the electric quantity to the secondary coil connected in parallel, and generates a control signal S1 to close the switch tube T8 when the release time reaches the preset time. The flyback transformer 3 uses mutual inductance to transfer the electric energy of the secondary coil to the primary coil, that is, the primary coil stores the electric quantity released by the lead-acid battery B1 to the secondary coil. Then the control chip 101 generates a control signal Prim_L to open the MOS tube T7 (transformer control unit 103). At this time, the electric quantity stored by the primary coil charges the battery pack (lead-acid batteries B1-B6) to be controlled, so as to transfer the excess electric quantity of the lead-acid battery B1 to the remaining lead-acid batteries. The battery voltages of all lead-acid batteries are collected again, and the difference between the voltage of the lead-acid battery B1 and the average voltage of all lead-acid batteries is determined. The above electric quantity transfer and average voltage determination process is repeated until the difference between the voltage of the lead-acid battery B1 and the average voltage of all lead-acid batteries is not greater than 0.1V. Stop the balancing step to realize the transfer of the excess electric quantity of the lead-acid battery B1 to all lead-acid batteries in the battery pack through the mutual inductance of the flyback transformer 3, balance the voltage of the lead-acid battery B1 and the voltage of the remaining lead-acid batteries, and realize the electric quantity balancing of the multiple lead-acid batteries in the battery pack.

[0078] Assuming that the voltage of the lead-acid battery B1 is higher than that of the remaining lead-acid batteries (the electric quantity of the lead-acid battery B1 is higher than the preset electric quantity), the lead-acid battery B1 is the target battery. At this time, the balancing type corresponding to the lead-acid battery B1 is top balancing, and when the working state of the battery pack to be controlled is the charging state, the lead-acid battery is connected with the charger. The balancing step performed by the balancing device is:

[0079] The control chip 101 generates a control signal S1 to control the switch T8 to turn on, thereby dividing the target battery current used by the charger to charge the lead-acid battery B1 into two paths: one for charging the lead-acid battery B1, and the other for balancing the battery pack current used to balance multiple lead-acid batteries. Specifically, the battery pack balancing current does not charge the lead-acid battery B1, but directly charges the secondary coil connected in parallel with the lead-acid battery B1. After the charging time of the secondary coil reaches a preset time, the control signal S1 for turning off the switch T8 is generated. The flyback transformer 3 uses mutual inductance to transfer the electrical energy of the secondary coil to the primary coil, that is, the primary coil stores the energy replenished by the battery pack balancing current to the secondary coil. Then, the control chip 101 generates a control signal Prim_L for turning on the MOS transistor T7 (transformer control unit 103). At this time, the primary coil and the charger jointly charge the battery pack to be controlled (lead-acid batteries B1-B6). , so as to transfer part of the power replenished for the target battery to multiple lead-acid batteries, collect the battery voltages of all lead-acid batteries again, determine the difference between the voltage of lead-acid battery B1 and the average voltage of all lead-acid batteries, repeat the above power transfer and average voltage determination process until the difference between the voltage of lead-acid battery B1 and the average voltage of all lead-acid batteries is no more than 0.1V, and then stop the balancing step. This is achieved during the charging process, so as to avoid the risk of overcharging and water loss of the lead-acid battery B1 with excess power after charging is completed, and to prevent the power gap between the lead-acid battery B1 and the other lead-acid batteries from increasing. By dividing the target battery current into two paths, the excess charging current is directed to the secondary coil of the flyback transformer 3 (to charge the secondary coil of the flyback transformer 3), and then transferred to all lead-acid batteries in the battery pack through the mutual inductance of the flyback transformer 3, so as to balance the voltage of the lead-acid battery B1 with the voltages of the other lead-acid batteries, thereby achieving power balancing among the multiple lead-acid batteries in the battery pack.

[0080] Assuming that the voltage of lead-acid battery B1 is lower than that of the other lead-acid batteries (the charge of lead-acid battery B1 is lower than the preset charge), lead-acid battery B1 is the target battery. At this time, the balancing type corresponding to lead-acid battery B1 is bottom balancing. At this time, when the working state of the battery pack to be controlled is the discharge state, the balancing steps performed by the balancing device are:

[0081] The control chip 101 generates control signals S1-S6 to control the switch tubes T1, T2, T3, T5, T6, and T8 to turn on, so that the lead-acid batteries B1-B6 release electricity to the secondary coils connected in parallel. After the electricity release time reaches the preset time, the control signals S1-S6 for turning off the switch tubes T1, T2, T3, T5, T6, and T8 are generated. The flyback transformer 3 uses mutual inductance to transfer the electrical energy of all secondary coils to the primary coil, that is, the primary coil stores the electricity released by the lead-acid batteries B1-B6 to the secondary coils connected in parallel with it. Then the control chip 101 generates a control signal S1 for turning on the switch tube T8. At this time, the primary coil discharges the stored electrical energy to the secondary coil connected in parallel with the lead-acid battery B1 through mutual inductance, so that the lead The lead-acid battery B1 and its parallel secondary coil discharge together to the load to transfer excess charge of the battery pack to be controlled to the load. The battery voltages of all the lead-acid batteries are collected again to determine the difference between the voltage of the lead-acid batteries B1-B6 and the average voltage of all the lead-acid batteries. The above charge transfer and average voltage determination process is repeated until the difference between the voltage of any one of the six lead-acid batteries and the average voltage of all the lead-acid batteries is no more than 0.1V. The balancing step is then stopped to transfer excess charge in the battery pack to the load through the mutual inductance of the flyback transformer 3. The lead-acid battery B1 and its parallel secondary coil discharge together to the load, reducing the discharge current of the lead-acid battery B1 with low charge to the load, thereby achieving charge balancing among the multiple lead-acid batteries in the battery pack.

[0082] Assuming that the voltage of lead-acid battery B1 is lower than that of the other lead-acid batteries (the charge of lead-acid battery B1 is lower than the preset charge), lead-acid battery B1 is the target battery. At this time, the balancing type corresponding to lead-acid battery B1 is bottom balancing. At this time, when the working state of the battery pack to be controlled is the static state, the balancing steps performed by the balancing device are:

[0083] The control chip 101 generates control signals S1-S6 to control the switch tubes T1, T2, T3, T5, T6, and T8 to turn on, so that the lead-acid battery group B1-B6 releases electricity to the secondary coil connected in parallel. After the electricity release time reaches the preset time, the control signal S1-S6 for turning off the switch tubes T1, T2, T3, T5, T6, and T8 is generated. The flyback transformer 3 uses mutual inductance to transfer the electrical energy of all secondary coils to the primary coil, that is, the primary coil stores the electricity released by the lead-acid batteries B1-B6 to the secondary coil connected in parallel with it. Then the control chip 101 generates a control signal S1 for turning on the switch tube T8. At this time, the primary coil transfers the stored electrical energy to the lead-acid battery B1 through mutual inductance. The parallel secondary coils are discharged, causing the secondary coils to charge the lead-acid battery B1, thereby transferring excess charge of the battery pack to be controlled to the lead-acid battery B1. The battery voltages of all the lead-acid batteries are collected again, and the difference between the voltage of the lead-acid batteries B1-B6 and the average voltage of all the lead-acid batteries is determined. The above charge transfer and average voltage determination process is repeated until the difference between the voltage of any one of the six lead-acid batteries and the average voltage of all the lead-acid batteries is no more than 0.1V. The balancing step is then stopped, and the excess charge in the battery pack is transferred to the lead-acid battery B1 with low charge through the mutual inductance of the flyback transformer 3, thereby balancing the voltage of the lead-acid battery B1 with the voltages of the remaining lead-acid batteries, thereby achieving charge balancing of the multiple lead-acid batteries in the battery pack.

[0084] Assuming that the voltage of lead-acid battery B1 is lower than that of the other lead-acid batteries (the charge of lead-acid battery B1 is lower than the preset charge), lead-acid battery B1 is the target battery. At this time, the balancing type corresponding to lead-acid battery B1 is bottom balancing. At this time, when the working state of the battery pack to be controlled is charging, the lead-acid battery is connected to the charger, and the balancing steps performed by the balancing device are as follows:

[0085] The control chip 101 generates control signals S1-S6 to control the switching transistors T1, T2, T3, T5, T6, and T8 to turn on, thereby dividing the target battery current of the charger for the controlled battery pack into two paths: one path is used to charge the controlled battery pack, and the other path is used to balance the multiple lead-acid batteries. Specifically, the battery balancing current does not charge the controlled battery pack, but directly charges the secondary coils connected in parallel with the lead-acid battery packs B1-B6. After the charging time of the secondary coils reaches a preset time, the control chip 101 generates control signals S1-S6 to control the switching transistors T1, T2, T3, T5, T6, and T8 to turn off. The flyback transformer 3 uses mutual inductance to transfer all the electrical energy in the secondary coils to the primary coil. That is, the primary coil stores the energy replenished by the battery balancing current. Then, the control chip 101 generates a control signal S1 to turn on the switching transistor T8. At this time, the primary coil discharges the stored electrical energy to the secondary coil connected in parallel with the lead-acid battery B1 through mutual inductance. The secondary coil and the charger jointly charge the lead-acid battery B1 to transfer part of the charge replenished by the battery pack to be controlled to the lead-acid battery B1. The battery voltages of all the lead-acid batteries are again collected to determine the difference between the voltage of the lead-acid battery B1 and the average voltage of all the lead-acid batteries. The above charge transfer and average voltage determination process is repeated until the difference between the voltage of any one of the six lead-acid batteries and the average voltage of all the lead-acid batteries is 0.1V. The balancing step is then stopped. This is achieved during the charging process to prevent the lead-acid battery B1 with too little charge from remaining in an undervoltage state after charging, resulting in performance degradation and an increasing gap in charge between the lead-acid batteries and the remaining lead-acid batteries. By dividing the target battery pack current into two paths, the excess charging current is directed to the secondary coil of the flyback transformer 3 (charging the secondary coil of the flyback transformer 3) and transferred to the lead-acid battery B1 with the low charge through the mutual inductance of the flyback transformer 3. The voltage of the lead-acid battery B1 is balanced with the voltages of the remaining lead-acid batteries, thereby achieving charge balancing among the multiple lead-acid batteries in the battery pack.

[0086] The above preset time can be set according to actual needs and is not limited here.

[0087] In one embodiment of the present invention, the balancing order of individual lead-acid batteries is determined based on the difference between the battery voltage of the individual lead-acid batteries and the average voltage. When the battery voltages of two or more lead-acid batteries are equal to the average voltage, the top balancing process takes precedence over the bottom balancing process.

[0088] For example, if the battery voltage of one lead-acid battery in the battery pack is 0.5V higher than the average voltage (top balancing), and the battery voltage of another lead-acid battery is 0.8V lower than the average voltage (bottom balancing), then the lead-acid battery with a voltage lower than the average voltage of 0.8V will be balanced first. If the battery voltage of one lead-acid battery in the battery pack is 0.5V higher than the average voltage (top balancing), and the battery voltage of another lead-acid battery is 0.5V lower than the average voltage (bottom balancing), then if the difference between the battery voltage and the average voltage is 0.5V, then the lead-acid battery with the top balancing type will be balanced first.

[0089] The active balancing device of the present invention utilizes the energy storage characteristics of the flyback transformer 3 to store excess energy of the lead-acid battery, and releases the stored energy to a lead-acid battery with lower energy or discharges it to a load, thereby avoiding a large voltage difference between multiple lead-acid batteries in the battery pack and extending the life of the battery pack.

[0090] The above are only preferred embodiments of the present application and are not intended to limit the present application. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present application should be included in the scope of protection of the present application.

Claims

1. A lead-acid battery active balancing method, applied to a battery pack to be controlled comprising a plurality of lead-acid batteries connected in series, wherein the battery pack to be controlled is used to discharge a load, characterized in that: include: Collecting the working status of the battery pack to be controlled and the battery voltage corresponding to the lead-acid battery; Determining a balancing type corresponding to the lead-acid battery according to the battery voltage; According to the working state and the balancing type, power balancing is performed on the multiple lead-acid batteries in the battery group to be controlled.

2. A lead-acid battery active equalization method according to claim 1, characterized in that: Determining a balancing type corresponding to the lead-acid battery according to the battery voltage includes: determining an average voltage of the plurality of lead-acid batteries based on the battery voltage; When the battery voltage of the lead-acid battery is greater than the average voltage, the balancing type corresponding to the lead-acid battery is top balancing; When the battery voltage of the lead-acid battery is lower than the average voltage, the balancing type corresponding to the lead-acid battery is bottom balancing.

3. The active equalization method for lead-acid batteries according to claim 2, characterized in that: The lead-acid battery is connected in parallel with the flyback transformer; When the working state is a discharging state, performing power balancing on the plurality of lead-acid batteries in the battery group to be controlled according to the working state and the balancing type includes: determining the battery capacity of the lead-acid battery according to the battery voltage; Determining a target battery in the battery group to be controlled according to the balancing type and the battery power; When the balancing type is top balancing, a lead-acid battery with a battery charge greater than a preset charge is determined as the target battery, the primary coil of the flyback transformer stores the charge released by the target battery to the secondary coil of the flyback transformer, and when the time for the target battery to release the charge equals the preset time, the primary coil of the flyback transformer uses the charge released by the target battery and the battery group to be controlled to simultaneously discharge the load to transfer the excess charge of the target battery to the load, and the battery voltage of the lead-acid battery is collected again to determine the average voltage of the multiple lead-acid batteries. The above process of charge transfer and average voltage determination is repeated until the difference between the battery voltage of the target battery and the average voltage is less than or equal to the preset voltage, and the target battery stops releasing charge; When the balancing type is bottom balancing, a lead-acid battery with a battery charge less than a preset charge is determined as the target battery, and the primary coil of the flyback transformer stores the charge released by the battery group to be controlled to the secondary coil of the flyback transformer. When the time for the lead-acid batteries in the battery group to be controlled to release the charge is equal to the preset time, the primary coil of the flyback transformer transfers the charge released by the battery group to be controlled to the secondary coil connected in parallel with the target battery. The target battery and the secondary coil connected in parallel with the target battery simultaneously discharge the load to transfer the excess charge of the battery group to be controlled to the load. The battery voltage of the lead-acid battery is collected again to determine the average voltage of the multiple lead-acid batteries. The above-mentioned charge transfer and average voltage determination process is repeated until the difference between the battery voltage of any lead-acid battery in the battery group to be controlled and the average voltage is less than or equal to the preset voltage, and the battery group to be controlled stops releasing charge.

4. The active equalization method for lead-acid batteries according to claim 2, characterized in that: The lead-acid battery is connected in parallel with the flyback transformer; When the working state is a static state, performing power balancing on the plurality of lead-acid batteries in the battery group to be controlled according to the working state and the balancing type includes: determining the battery capacity of the lead-acid battery according to the battery voltage; Determining a target battery in the battery group to be controlled according to the balancing type and the battery power; When the balancing type is top balancing, a lead-acid battery with a battery charge greater than a preset charge is determined as the target battery, the primary coil of the flyback transformer stores the charge released by the target battery to the secondary coil of the flyback transformer, and when the time for the target battery to release charge equals the preset time, the primary coil of the flyback transformer uses the charge released by the target battery to charge the battery group to be controlled, so as to transfer excess energy of the target battery to each lead-acid battery, and the battery voltage of the lead-acid battery is collected again to determine the average voltage of the multiple lead-acid batteries, until the difference between the battery voltage of the target battery and the average voltage equals the preset voltage, at which point the target battery stops releasing charge; When the balancing type is bottom balancing, a lead-acid battery with a battery charge less than a preset charge is determined as the target battery, and the primary coil of the flyback transformer stores the charge released by the battery group to be controlled to the secondary coil of the flyback transformer. When the time for the lead-acid batteries in the battery group to be controlled to release the charge is equal to the preset time, the primary coil of the flyback transformer transfers the charge released by the battery group to be controlled to the secondary coil connected in parallel with the target battery, and charges the target battery through the secondary coil connected in parallel with the target battery to transfer the excess charge of the battery group to be controlled to the target battery. The battery voltage of the lead-acid battery is collected again, and the average voltage of the multiple lead-acid batteries is determined. The above-mentioned charge transfer and average voltage determination process is repeated until the difference between the battery voltage of any lead-acid battery in the battery group to be controlled and the average voltage is equal to the preset voltage, and the battery group to be controlled stops releasing charge.

5. The active equalization method for lead-acid batteries according to claim 2, characterized in that: The lead-acid battery is connected in parallel with the flyback transformer; When the working state is the charging state, the lead-acid battery is connected to the charger, and according to the working state and the balancing type, the multiple lead-acid batteries in the battery group to be controlled are balanced in terms of power, including: determining the battery capacity of the lead-acid battery according to the battery voltage; Determining a target battery in the battery group to be controlled according to the balancing type and the battery power; When the balancing type is top balancing, a lead-acid battery having a battery charge greater than a preset charge is determined as the target battery, a target battery current used by the charger to charge the target battery is divided into a charging current for charging the target battery and a battery pack balancing current, the primary coil of the flyback transformer stores the charge replenished by the battery pack balancing current to the secondary coil of the flyback transformer, and when the charging time of the secondary coil of the flyback transformer equals a preset time, the primary coil of the flyback transformer uses the charge replenished by the battery pack balancing current to charge the secondary coil of the flyback transformer and the charger simultaneously to charge the battery pack to be controlled, thereby transferring part of the charge replenished to the target battery to each lead-acid battery, collecting the battery voltage of the lead-acid battery again, and determining the average voltage of the multiple lead-acid batteries. The above-mentioned charge transfer and average voltage determination process is repeated until the difference between the battery voltage of the target battery and the average voltage equals the preset voltage, and then charge balancing of the multiple lead-acid batteries in the battery pack to be controlled is stopped; When the balancing type is bottom balancing, a lead-acid battery with a battery charge less than a preset charge is determined as the target battery. The target battery group current used by the charger to charge the battery group to be controlled is divided into a charging current for the battery group to be controlled and a battery balancing current. The primary coil of the flyback transformer stores the charge supplied to the secondary coil of the flyback transformer by the battery balancing current. When the charging time of the secondary coil of the flyback transformer equals a preset time, the primary coil of the flyback transformer transfers the charge supplied to the secondary coil of the flyback transformer by the battery balancing current to the secondary coil connected in parallel with the target battery. The target battery is charged simultaneously by the secondary coil connected in parallel with the target battery and the charger, thereby transferring part of the charge supplied to the battery group to the target battery. The battery voltage of the lead-acid battery is again collected to determine the average voltage of the multiple lead-acid batteries. The above energy transfer and average voltage determination process is repeated until the difference between the battery voltage of any lead-acid battery in the battery group to be controlled and the average voltage equals the preset voltage, at which point energy balancing of the multiple lead-acid batteries in the battery group to be controlled is stopped.

6. A lead-acid battery active equalization device, applied to the lead-acid battery active equalization method according to claims 1-5, characterized in that: include: Control module, switch module, flyback transformer and sampling module; The control module is connected to the switch module, the flyback transformer, and the sampling module; the flyback transformer is connected to the lead-acid battery, the switch module, and the sampling module; the lead-acid battery is connected to the switch module; The sampling module generates a feedback signal including the working status and the battery voltage, the control module generates a control signal according to the feedback signal, and the switch module closes or disconnects the connection between the lead-acid battery and the flyback transformer according to the control signal, so as to store the electricity discharged by the target battery or the battery pack to be controlled in the flyback transformer; The flyback transformer switches the connection between the charge and discharge states according to the control signal to transfer the electric quantity to the target battery or the battery group to be controlled.

7. The lead-acid battery active equalization device according to claim 6, characterized in that: The flyback transformer includes a primary coil and secondary coils having the same number as the lead-acid batteries; the primary coil is connected to the lead-acid batteries, the sampling module, and the control module, and the secondary coil is connected to the switch module.

8. The lead-acid battery active equalization device according to claim 7, characterized in that: The switch module includes a plurality of switch units with the same structure, and the number of the switch units is the same as the number of the lead-acid batteries; the switch units are connected to the lead-acid batteries, the control module, and the secondary coil.

9. The lead-acid battery active equalization device according to claim 8, characterized in that: The switch unit includes a switch tube and a signal output circuit. The switch tube is connected to the lead-acid battery and the signal output circuit. The signal output circuit is connected to the secondary coil.

10. The lead-acid battery active equalization device according to claim 9, characterized in that: The control module includes a processor and a memory, wherein the memory stores at least one instruction, at least one program, code set, or instruction set, and the at least one instruction, at least one program, code set, or instruction set is loaded and executed by the processor to implement a lead-acid battery active balancing method according to any one of claims 1 to 5.

Images