Battery, full-time equalization method and device thereof, and controller

Abstract

The invention discloses a battery and a full-time equalization method and device thereof, and a controller, and the method comprises the steps: collecting the voltage of each single cell in the battery in real time when the battery is in a charging stage, and carrying out the equalization control of the single cells of the battery through voltage difference equalization if the voltages of all single cells in the battery meet a first equalization condition, and when the battery is in a standing stage after being fully charged, estimating the capacity of each single battery cell in the battery, and if the capacities of all the single battery cells in the battery meet a second equalization condition, performing equalization control on the single battery cells of the battery by using capacity difference equalization. Balancing control is carried out based on the voltage difference in the charging stage, and balancing control is carried out based on the capacity difference in the standing stage after full charging, so that the battery balancing effect is improved.

Description

Technical Field

[0001] The present invention relates to the field of battery technology, and in particular to a battery and a full-time balancing method, device and controller thereof. Background Art

[0002] With the rapid development of battery technology, lithium batteries are increasingly used in the fields of automobiles, model airplanes, etc. Since the voltage of a single lithium battery is relatively low, a battery pack consisting of multiple lithium batteries connected in series is often used in the fields of automobiles, model airplanes, etc., and each lithium battery is used as a single cell in the battery pack. In order to reduce the impact of inconsistent battery packs, improve the performance of battery packs, extend the service life of battery packs, and ensure the safety and reliability of battery use, it is usually necessary to balance the battery pack.

[0003] In the prior art, the mainstream balancing solutions are passive balancing and active balancing. When passive balancing is used, the imbalance of single cells can generally be identified at the end of the charging and discharging process. In order to maintain the overall power, a strategy of balancing at the end of charging and unbalancing during discharge is often adopted. Therefore, the time from identifying the imbalance of cells to the end of full charging is short, the balancing time is short, and the balancing effect is not obvious; while the hardware circuit of active balancing is usually complex in design, expensive, and the software algorithm logic is complex, and the development is difficult.

[0004] Therefore, how to manage the battery balance to improve the battery balance effect has become an urgent problem to be solved. Summary of the invention

[0005] Based on this, a battery and a full-time balancing method, device, and controller thereof are provided to solve the problem of balancing management of the battery to improve the balancing effect of the battery.

[0006] In a first aspect, an embodiment of the present invention provides a full-time balancing method for a battery, the full-time balancing method comprising the following steps:

[0007] When the battery is in the charging stage, the voltage of each single cell in the battery is collected in real time, and if the voltages of all the single cells in the battery meet the first balancing condition, the single cells of the battery are balanced by using voltage difference balancing;

[0008] When the battery is in a resting stage after being fully charged, the capacity of each single cell in the battery is estimated, and if the capacity of all single cells in the battery meets a second balancing condition, the single cells of the battery are balanced by using capacity difference balancing.

[0009] In a second aspect, an embodiment of the present invention provides a full-time balancing device for a battery, the full-time balancing device comprising:

[0010] A voltage difference balancing module is used to collect the voltage of each single cell in the battery in real time when the battery is in a charging stage, and if the voltage of all the single cells in the battery meets a first balancing condition, use voltage difference balancing to perform balancing control on the single cells of the battery;

[0011] The capacity difference balancing module is used to estimate the capacity of each single cell in the battery when the battery is in a static stage after being fully charged, and if the capacity of all the single cells in the battery meets the second balancing condition, use capacity difference balancing to balance the single cells of the battery.

[0012] In a third aspect, an embodiment of the present invention provides a controller, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor implements the steps of the above-mentioned full-time balancing method for the battery when executing the computer program.

[0013] In a fourth aspect, an embodiment of the present invention provides a battery, comprising a battery cell and the controller of the third aspect.

[0014] Compared with the prior art, the embodiments of the present invention have the following beneficial effects: when the battery is in the charging stage, the present invention collects the voltage of each single cell in the battery in real time; if the voltages of all the single cells in the battery meet the first balancing condition, the single cells of the battery are balanced and controlled by using voltage difference balancing; when the battery is in the static stage after being fully charged, the capacity of each single cell in the battery is estimated; if the capacity of all the single cells in the battery meets the second balancing condition, the single cells of the battery are balanced and controlled by using capacity difference balancing.

[0015] Among them, during the charging process, since the voltage change of the single cell is more intuitive and accurate, therefore, in the charging stage, the voltage difference equalization is performed based on the real-time collected voltage, which can directly adjust the voltage difference of the single cell, quickly reduce the voltage difference, and improve the accuracy and efficiency of the equalization; in the static stage after full charging, since the voltage difference between different single cells will become very small with the static time, the use of voltage difference to balance the single cells at this time may cause mis-balancing due to measurement errors. Therefore, in the static stage after full charging, the capacity difference equalization is performed based on the estimated capacity at the time of full charging, which can make full use of the static time for long-term equalization processing, so that each single cell can release energy more evenly, improving the accuracy of the balance and the energy utilization rate. Therefore, the equalization control is performed based on the voltage difference in the charging stage, and the equalization control is performed based on the capacity difference in the static stage after full charging, which improves the effect of battery balancing. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings required for use in the description of the embodiments of the present invention will be briefly introduced below. Obviously, the accompanying drawings in the following description are only some embodiments of the present invention. For ordinary technicians in this field, other accompanying drawings can be obtained based on these accompanying drawings without paying creative labor.

[0017] Figure 1 It is a flowchart of a full-time balancing method for a battery provided in Embodiment 1 of the present invention;

[0018] Figure 2 It is a schematic diagram of the overall process of a full-time balancing method for a battery provided in the first embodiment of the present invention;

[0019] Figure 3 This is a schematic diagram of a switching process of voltage difference balancing and capacity difference balancing provided in the first embodiment of the present invention;

[0020] Figure 4 It is a schematic diagram of a process of closing balancing provided by the first embodiment of the present invention;

[0021] Figure 5 is a flowchart of a full-time balancing method for a battery provided in Embodiment 2 of the present invention;

[0022] Figure 6 1 is a flow chart of a full-time balancing method for a battery provided in Embodiment 3 of the present invention;

[0023] Figure 7 1 is a flow chart of a full-time balancing method for a battery provided in a fourth embodiment of the present invention;

[0024] Figure 8 It is a flowchart of a full-time balancing method for a battery provided in Embodiment 5 of the present invention;

[0025] Fig. 9 1 is a flow chart of a full-time balancing method for a battery provided in Embodiment 6 of the present invention;

[0026] Fig.10 1 is a flow chart of a full-time balancing method for a battery provided in Embodiment 7 of the present invention;

[0027] Fig.11 1 is a schematic structural diagram of a full-time balancing device for a battery provided in Embodiment 8 of the present invention;

[0028] Fig.12 It is a structural diagram of a controller provided in Embodiment 9 of the present invention. DETAILED DESCRIPTION

[0029] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0030] It should be understood that the order of execution of the steps in the following embodiments does not imply a precedence of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of the present invention.

[0031] like Figure 1 FIG. 1 is a flow chart of a full-time balancing method for a battery provided in Embodiment 1 of the present invention. The full-time balancing method includes the following steps:

[0032] Step S101: when the battery is in the charging stage, the voltage of each single cell in the battery is collected in real time. If the voltages of all the single cells in the battery meet the first balancing condition, the single cells of the battery are balanced by using voltage difference balancing.

[0033] In this embodiment, in the fields of automobiles, model airplanes, etc., since the voltage of a single lithium battery is relatively low, multiple lithium batteries are usually used in series to form a smart battery, and each lithium battery is a single cell in the smart battery. Voltage difference balancing may refer to a strategy for balancing the single cells of the battery that is judged and activated based on the voltage of the single cell, and the first balancing condition may refer to a condition for starting voltage difference balancing.

[0034] For example, when the battery is in the charging stage, the voltage of each single cell in the battery is collected in real time to determine the highest and lowest voltages of all the single cells collected. If the difference between the highest and lowest voltages meets the preset value, the balancing control of the single cells of the battery is turned on to determine the single cells that need to be balanced and balance them.

[0035] Step S102: when the battery is in a resting stage after being fully charged, the capacity of each single cell in the battery is estimated, and if the capacity of all single cells in the battery meets the second balancing condition, the single cells of the battery are balanced by using capacity difference balancing.

[0036] In this embodiment, the rest stage after full charge may refer to a period of time during which the battery does not perform any charging or discharging operations after completing its charging process and reaching a fully charged state. During the rest stage after full charge, the battery does not receive energy input from an external power source, nor does it provide energy output to an external load. Capacity difference balancing may refer to a strategy for balancing control of the battery's single cells that is judged and activated based on the capacity of the single cells. The second balancing condition may refer to a condition that needs to be met by the single cells for capacity difference balancing when the battery is in the rest stage after full charge.

[0037] For example, when the battery is in the static stage after being fully charged, the capacity of each single cell in the battery is estimated, and the minimum capacity of all the collected single cells is determined. For any single cell, if the capacity difference between the capacity of the single cell and the minimum capacity meets the preset value, it is determined that the single cell meets the second balancing condition, and the single cell is balanced and controlled.

[0038] For example, Figure 2 FIG. 1 is a schematic diagram of the overall process of a full-time balancing method for a battery provided in Embodiment 1 of the present invention. The system periodically determines and starts the balancing task for the battery with a period of 100 ms.

[0039] If the battery is in the charging stage, the highest single cell voltage is greater than or equal to 3.4V, the voltage difference between the highest single cell voltage and the lowest single cell voltage is greater than or equal to 30mV, and balancing control is allowed, that is, the balancing prohibition flag is not set, then enter the voltage difference balancing mode. If any of the above conditions for starting voltage difference balancing are not met, return to continue the judgment of the balancing mode; in the voltage difference balancing mode, for any single cell, if the voltage of the single cell is greater than or equal to the average voltage of 3V, it is determined that the single cell is the first cell that needs to be balanced. If it is less than the average voltage of 3V, it returns to continue to determine whether it is the first cell that needs to be balanced. According to the judgment, all the first balancing cells that need to be turned on in the battery are divided into two groups, and the balancing of the two groups is periodically and alternately turned on with a period of 5S; during the balancing process, it is judged whether to turn off the voltage difference balancing. If the current voltage of any first balancing cell that needs to be turned on is lower than the voltage of all other single cells, the balancing of the first balancing cell that needs to be turned on is turned off, and the current voltage is used as the balancing stop voltage. If the voltage of any first balancing cell that needs to be turned on is lower than the balancing stop voltage, the balancing of the corresponding first balancing cell that needs to be turned on is turned off. If any of the above conditions for turning off the voltage difference balancing are not met, it returns to continue to judge whether to turn off the voltage difference balancing.

[0040] If the highest single cell capacity of the battery is greater than or equal to 99%, the charging current is less than or equal to 200mA, and balancing control is allowed, that is, the prohibition balancing flag is not set, it is determined that the battery is in a fully charged state and enters the capacity difference balancing mode. If any of the above conditions for determining that it is fully charged are not met, then the judgment of the balancing mode is returned to continue. In the static stage after full charging in the capacity difference balancing mode, for any single cell, if the difference between the capacity of the single cell and the capacity of the lowest single cell is greater than or equal to 1%, then the single cell is determined to be the second cell that needs to be balanced. If the capacity difference is less than 1%, then the judgment of whether it is the second cell that needs to be balanced is returned to continue. All the second cells that need to be balanced in the battery are divided into two groups, and the balancing of the two groups is periodically turned on with a period of 5S. In the balancing process, it is judged whether to turn off the capacity difference balancing. If the time for which any second cell that needs to be balanced has been balanced is greater than the balancing time, the balancing is turned off. If the time for which any second cell that needs to be balanced has been balanced is less than the balancing time, then the judgment of whether to turn off the capacity difference balancing is returned to continue.

[0041] For example, Figure 3 As shown, it is a schematic diagram of a switching process of voltage difference equalization and capacity difference equalization provided by the first embodiment of the present invention. In the voltage difference equalization mode, if the duration of the highest single cell voltage being greater than or equal to the voltage for determining that the battery is in a fully charged state is more than 1S, the voltage difference equalization is turned off and switched to the capacity difference equalization mode. If it is not satisfied, it returns to continue the above judgment of whether to switch to the capacity difference equalization mode; in the capacity difference equalization mode, if the charging state is entered again after entering the over-discharge or static state, the voltage difference equalization mode is switched when the first equalization condition is met.

[0042] For example, Figure 4The figure shows a flow chart of closing balancing provided by the first embodiment of the present invention. During the balancing process, if the battery is in a discharging state, the balancing temperature is too high, the battery cell temperature is too high / too low and permanently fails, the battery cell voltage is too high / too low and permanently fails, the temperature / voltage sampling is abnormal, or the communication is abnormal, the balancing prohibition flag is set, and the voltage difference balancing mode is switched to the capacity difference balancing mode, or the balancing prohibition flag is set, then the balancing of all the cells that need to be balanced is closed. For any cell that needs to be balanced, check whether the channel voltage of the cell that is balanced is less than the difference between the minimum voltage of the cell that is not balanced and 10mV. If it is less than, close the balancing of its current channel. If it is greater than or equal to, close the balancing of the cell. The balancing mode of the balancing cell to be turned on is judged. If it is in the voltage difference balancing mode, it is detected whether the current voltage of the first balancing cell to be turned on is less than the voltage of all other single cells, or the voltage of the first balancing cell to be turned on is less than the balancing stop voltage. If it is satisfied, the balancing of its current channel is turned off. If it is not satisfied, it returns to continue to judge whether to turn off the balancing of its channel; if it is in the capacity difference balancing mode, it is detected whether the balancing time of the second balancing cell to be turned on is greater than the balancing time. If it is greater, the balancing is turned off. If it is not satisfied, it returns to continue to judge whether to turn off the balancing of its channel.

[0043] In this embodiment, during the charging process, since the voltage change of the single cell is more intuitive and accurate, therefore, in the charging stage, the voltage difference equalization is performed based on the real-time collected voltage, and the voltage difference of the single cell can be directly adjusted, and the voltage difference can be quickly reduced, thereby improving the accuracy and efficiency of the equalization; in the static stage after full charging, since the voltage difference between different single cells will become very small with the static time, the use of voltage difference to balance the single cell may cause mis-balancing due to measurement errors. Therefore, in the static stage after full charging, the capacity difference equalization is performed based on the estimated capacity at the time of full charging, and the static time can be fully utilized for long-term equalization processing, so that each single cell can release energy more evenly, thereby improving the accuracy and energy utilization of the equalization. Therefore, the equalization control is performed based on the voltage difference in the charging stage, and the equalization control is performed based on the capacity difference in the static stage after full charging, thereby improving the effect of battery equalization.

[0044] like Figure 5 FIG. 1 is a flow chart of a full-time balancing method for a battery provided in the second embodiment of the present invention. In the above step S101, if the voltages of all single cells meet the first balancing condition, the single cells of the battery are balanced by using voltage difference balancing, which may include the following steps:

[0045] Step S501: Determine the highest cell voltage and the lowest cell voltage from the voltages of all the single cells in the battery.

[0046] Step S502: If the highest cell voltage is greater than the first voltage value, then detecting whether the voltage difference between the highest cell voltage and the lowest cell voltage is greater than the second voltage value.

[0047] Step S503: if it is detected that the voltage difference is greater than the second voltage value, it is determined that the voltages of all the single cells in the battery meet the first balancing condition, and voltage difference balancing is used to perform balancing control on the single cells of the battery.

[0048] In this embodiment, the highest single cell voltage may refer to the highest voltage of all single cells in the battery, the lowest single cell voltage may refer to the lowest voltage of all single cells in the battery, the first voltage value may refer to the voltage value that the highest single cell voltage should satisfy when voltage difference balancing is turned on, and the second voltage value may refer to the voltage value that the voltage difference should satisfy when voltage difference balancing is turned on.

[0049] For example, if the first voltage value is 3.4V and the second voltage value is 30mV, if the highest single cell voltage is 3.5V and the lowest single cell voltage is 3.2V, it can be determined that the highest single cell voltage 3.5V is greater than the first voltage value 3.4V, and the voltage difference between the highest single cell voltage 3.5V and the lowest single cell voltage 3.2V is 0.3V, that is, 300mV, then it can be determined that the voltage difference 300mV is greater than the second voltage value of 30mV, and it can be determined that the voltages of all single cells in the battery meet the first balancing condition, then the voltage difference balancing is used to balance the single cells of the battery.

[0050] In this embodiment, if the highest single cell voltage is greater than the first voltage value, and the voltage difference between the highest single cell voltage and the lowest single cell voltage is greater than the second voltage value, the balancing control of the battery is turned on to prevent the single cell corresponding to the highest single cell voltage from being further overcharged, and reduce the voltage difference between the single cells, so that during the charging process, all the single cells in the battery can be charged more evenly and fully, thereby improving the overall performance of the battery and extending the battery life.

[0051] like Figure 6 As shown, it is a schematic flow chart of a full-time balancing method for a battery provided in the third embodiment of the present invention. In the above step S101, the voltage difference balancing is used to balance the single cells of the battery, which may include the following steps:

[0052] Step S601: Calculate the average voltage of all single cells in the battery. For any single cell in the battery, if the voltage of the single cell is greater than the average voltage, and the voltage difference between the voltage of the single cell and the lowest single cell voltage is greater than a second voltage value, then the single cell is identified as the first cell to be balanced.

[0053] Step S602: Divide all first balancing cells that need to be turned on into two groups.

[0054] Step S603: according to a preset first period, periodically start the balancing control of the two groups.

[0055] In this embodiment, the average voltage may refer to the average value of the voltages of all single cells in the battery, the first balancing cell that needs to be turned on may refer to the single cell that needs to be voltage balanced, and the preset first period may refer to the period of balancing control of two groups of first balancing cells that need to be turned on, wherein two adjacent first balancing cells that need to be turned on are not in the same group.

[0056] For example, for any single cell in the battery, if the voltage of the single cell is greater than the average voltage, and the voltage difference between the voltage of the single cell and the lowest single cell voltage is greater than the second voltage value, the single cell is the first cell that needs to be turned on for balancing, and according to the principle that adjacent single cells cannot turn on balancing control at the same time, all the first cells that need to be turned on for balancing are divided into two groups to turn on balancing control. With the first cell that needs to be turned on for balancing with the highest voltage as the center, the single cells on its left and right sides are traversed one by one, and according to the principle that adjacent single cells cannot turn on balancing control at the same time, all the first cells that need to be turned on for balancing are divided into two groups. If the first period is preset to be 5S, after the first group turns on balancing control and the second group turns off balancing control for 5S, the second group turns on balancing control and the first group turns off balancing control for 5S, so as to periodically turn on the balancing control of the two groups.

[0057] In this embodiment, the first balancing cells that need to be turned on are divided into two groups, and the balancing control of the two groups is periodically turned on according to the preset first period, so as to avoid the situation that two adjacent first balancing cells that need to be turned on in series discharge at the same time and interfere with each other, and prevent the problem of excessive temperature rise during the balancing process, thereby protecting the safety of the battery during the balancing process and extending the battery life.

[0058] like Figure 7 FIG. 1 is a flow chart of a full-time balancing method for a battery provided in Embodiment 4 of the present invention. After periodically starting the balancing control of the two groups according to the preset first cycle in the above step S603, the following steps may also be included:

[0059] Step S701: for any first balancing cell that needs to be turned on, if the current voltage of the first balancing cell that needs to be turned on is lower than the voltages of other single cells in the battery, then turning off the balancing control of the first balancing cell that needs to be turned on.

[0060] Step S702: taking the current voltage as the balancing stop voltage, if the voltage of any first balancing cell that needs to be turned on is lower than the balancing stop voltage, turning off the balancing control of the corresponding first balancing cell that needs to be turned on.

[0061] In this embodiment, the current voltage may refer to the voltage of the first balancing cell that needs to be turned on during the balancing process, and the balancing stop voltage may refer to the voltage value that needs to be met when the balancing control of the first balancing cell that needs to be turned on is turned off.

[0062] Specifically, during the balancing process, for any first balancing cell that needs to be turned on, if the current voltage of the first balancing cell that needs to be turned on is the lowest voltage of all single cells in the battery, the balancing of the first balancing cell that needs to be turned on is turned off, and the current voltage is marked as the balancing stop voltage of other first balancing cells that need to be turned on; if the voltage of any first balancing cell that needs to be turned on is lower than the balancing stop voltage, the balancing control of the corresponding first balancing cell that needs to be turned on is turned off.

[0063] In this embodiment, by setting the balancing stop voltage, when the voltage of the first balancing cell to be turned on is lower than the balancing stop voltage, the balancing control is turned off, so that the balancing process can be controlled more accurately, unnecessary energy transfer and loss can be avoided, the overall time of the balancing control can be reduced, and the balancing efficiency can be improved.

[0064] like Figure 8 As shown, it is a flowchart of a full-time balancing method for a battery provided in Embodiment 5 of the present invention. Before the battery is in the resting stage after being fully charged in the above step S102, the following steps may also be included:

[0065] Step S801: Determine the highest single cell capacity from the capacities of all single cells in the battery.

[0066] Step S802: If the highest cell capacity is greater than the first capacity value, then detecting whether the charging current of the battery is less than the first current value.

[0067] Step S803: If it is detected that the charging current is less than the first current value, it is determined that the battery is in a fully charged state.

[0068] In this embodiment, the maximum single cell capacity may refer to the maximum capacity of all single cells in the battery, the first capacity value may refer to the capacity value that the maximum single cell capacity should satisfy when the battery is fully charged, and the first current value may refer to the current value that the charging current of the battery should satisfy when the battery is fully charged.

[0069] Specifically, the capacity of a single battery cell can be estimated when fully charged based on a pre-trained capacity estimation model. The model has learned the relationship between the battery cell capacity and various parameters such as voltage, current, and temperature through training with a large amount of charging and discharging data. Then, when fully charged, the model can be used to estimate the capacity of a single battery cell based on current parameters such as voltage, current, and temperature.

[0070] Optionally, the capacity corresponding to each battery voltage under different temperatures and charging rates can be tested, and a mapping table of charging voltage and capacity under different temperatures and charging rates can be pre-established based on the test results. The capacity of a single battery cell can be determined based on the voltage parameters collected in real time in combination with the voltage-capacity mapping table.

[0071] For example, if the first capacity value is the capacity corresponding to a fully charged battery, if the first capacity value is 99%, the first current value is 50mA, if the maximum cell capacity is 100%, the charging current is 40mA, the maximum cell capacity of 100% is greater than the first capacity value of 99%, and the charging current of 40mA is less than the first current value of 50mA, then in the trickle charging stage, the battery is charged to the maximum cell capacity of 100% with a current of 40mA, and it can be determined that the battery is in a fully charged state.

[0072] In this embodiment, if the highest single cell capacity is greater than the first capacity value and the charging current is less than the first current value, it is determined that the battery is fully charged, and thus during the static stage after full charging, the balancing control of the battery is turned on to ensure that each single cell in the battery pack is fully charged, avoiding the occurrence of unbalanced power during use, thereby improving the overall performance of the battery and extending the battery life.

[0073] like Fig. 9 FIG. 1 is a flow chart of a full-time balancing method for a battery provided in Embodiment 6 of the present invention. In the above step S102, if the capacities of all the single cells in the battery meet the second balancing condition, the single cells of the battery are balanced by using capacity difference balancing, which may include the following steps:

[0074] Step S901: Determine the lowest single cell capacity from the capacities of all single cells in the battery.

[0075] Step S902: for any single cell in the battery, if the capacity difference between the single cell capacity and the lowest single cell capacity is greater than a second capacity value, it is determined that the single cell meets the second balancing condition, and the single cell is set as the second balancing cell to be started.

[0076] Step S903: Divide all the second balancing cells that need to be turned on into two groups.

[0077] Step S904: according to the preset second period, periodically start the balancing control of the two groups.

[0078] In this embodiment, the minimum single cell capacity may refer to the minimum capacity of all single cells in the battery, the second capacity value may refer to the capacity difference of the single cells for capacity difference balancing, the capacity value that should be met, the second balancing cell that needs to be turned on may refer to the single cell for which capacity difference balancing is required, and the preset second cycle may refer to the cycle for performing balancing control on the two groups of second balancing cells that need to be turned on, wherein two adjacent second balancing cells that need to be turned on are not in the same group.

[0079] For example, if the capacity difference between the capacity of a single cell and the minimum single cell capacity is greater than 1%, it is determined that the single cell meets the second balancing condition, and the single cell is defined as the second balancing cell to be enabled. All second balancing cells to be enabled are grouped and periodically balanced. For details, please refer to the contents in steps S602 to S603.

[0080] In this embodiment, the second balancing cells that need to be turned on are divided into two groups, and the balancing control of the two groups is periodically turned on according to the preset second period, so as to avoid the situation that two adjacent second balancing cells that need to be turned on in series discharge at the same time and interfere with each other, and prevent the problem of excessive temperature rise during the balancing process, thereby protecting the safety of the battery during the balancing process and extending the battery life.

[0081] like Fig.10 FIG. 1 is a flow chart of a full-time balancing method for a battery provided in Embodiment 7 of the present invention. After periodically starting the balancing control of the two groups according to the preset second period in the above step S904, the following steps may also be included:

[0082] Step S1001: for any second balancing cell that needs to be turned on, calculating the balancing time of the second balancing cell that needs to be turned on according to a preset balancing current.

[0083] Step S1002: If the time of the balancing control on the second balancing cell that needs to be turned on is greater than the balancing time, then turning off the balancing control on the second balancing cell that needs to be turned on.

[0084] In this embodiment, the preset balancing current may refer to a balancing current for capacity difference balancing, and the balancing time may refer to a time for balancing the capacity difference of the second balancing cell to be turned on.

[0085] Specifically, for any second balancing cell that needs to be turned on, the amount of charge that needs to be transferred is determined, and the balancing time can be calculated by dividing the amount of charge that needs to be transferred by the balancing current. In order to prevent over-balancing, an upper limit value can be set for the balancing time. For example, the upper limit of the balancing time can be 4 hours. If the time for which any second balancing cell that needs to be turned on has been under balancing control is greater than the balancing time, the balancing control of the cell is turned off.

[0086] In this embodiment, by calculating the balancing time and shutting down the balancing control when the balancing time is reached, the balancing process can be controlled more accurately, unnecessary energy transfer and loss can be avoided, the overall balancing control time can be reduced, and the balancing efficiency can be improved.

[0087] like Fig.11 As shown, a full-time balancing device for a battery provided in Embodiment 8 of the present invention is provided. The full-time balancing device for a battery corresponds one-to-one to the full-time balancing method for a battery in the above embodiment. The full-time balancing device for a battery includes a voltage difference balancing module 1101 and a capacity difference balancing module 1102. The functional modules are described in detail as follows:

[0088] The voltage difference equalization module 1101 is used to collect the voltage of each single cell in the battery in real time when the battery is in the charging stage, and if the voltage of all the single cells in the battery meets the first equalization condition, use voltage difference equalization to perform equalization control on the single cells of the battery;

[0089] The capacity difference balancing module 1102 is used to estimate the capacity of each single cell in the battery when the battery is in a static stage after being fully charged, and if the capacity of all single cells in the battery meets the second balancing condition, use capacity difference balancing to balance the single cells of the battery.

[0090] Optionally, the voltage difference equalization module 1101 includes:

[0091] A first determining unit, used to determine a maximum cell voltage and a minimum cell voltage from the voltages of all the single cells in the battery;

[0092] A first detection unit, configured to detect whether a voltage difference between the highest cell voltage and the lowest cell voltage is greater than a second voltage value if the highest cell voltage is greater than a first voltage value;

[0093] The second determining unit is configured to determine that the voltages of all the single cells in the battery meet the first balancing condition if it is detected that the voltage difference is greater than the second voltage value, and to perform balancing control on the single cells of the battery using the voltage difference balancing.

[0094] Optionally, the voltage difference equalization module 1101 includes:

[0095] a third determining unit, configured to calculate an average voltage of all single cells in the battery, and for any single cell in the battery, if the voltage of the single cell is greater than the average voltage, and the voltage difference between the voltage of the single cell and the lowest single cell voltage is greater than the second voltage value, then the single cell is defined as a first cell requiring balancing;

[0096] A first grouping unit is used to divide all first balancing cells that need to be turned on into two groups, wherein two adjacent first balancing cells that need to be turned on are not in the same group;

[0097] The first balancing unit is used to periodically start balancing control on the two groups according to a preset first period.

[0098] Optionally, the voltage difference equalization module 1101 further includes:

[0099] A first shut-down unit is configured to shut down the balancing control of any first balancing cell that needs to be turned on if the current voltage of the first balancing cell that needs to be turned on is lower than the voltages of other single cells in the battery;

[0100] The second closing unit is configured to use the current voltage as a balancing stop voltage, and if the voltage of any first balancing cell to be turned on is lower than the balancing stop voltage, close the balancing control of the corresponding first balancing cell to be turned on.

[0101] Optionally, the full-time balancing device of the battery further includes:

[0102] A fourth determining unit, configured to determine a maximum single cell capacity from the capacities of all single cells in the battery;

[0103] a second detection unit, configured to detect whether the charging current of the battery is less than a first current value if the highest single cell capacity is greater than a first capacity value;

[0104] A fifth determining unit is configured to determine that the battery is in a fully charged state if it is detected that the charging current is less than the first current value.

[0105] Optionally, the capacity difference balancing module 1102 includes:

[0106] a sixth determining unit, configured to determine a minimum single cell capacity from the capacities of all single cells in the battery;

[0107] a seventh determining unit, configured to determine, for any single cell in the battery, that the single cell satisfies the second balancing condition and set the single cell as a second cell requiring balancing if the difference between the capacity of the single cell and the minimum single cell capacity is greater than a second capacity value;

[0108] A second grouping unit is used to divide all the second balancing cells that need to be turned on into two groups, wherein two adjacent second balancing cells that need to be turned on are not in the same group;

[0109] The second balancing unit is used to periodically start the balancing control of the two groups according to a preset second period.

[0110] Optionally, the capacity difference balancing module 1102 further includes:

[0111] A calculation unit, configured to calculate, for any second balancing cell that needs to be turned on, a balancing time of the second balancing cell that needs to be turned on according to a preset balancing current;

[0112] The third shut-down unit is configured to shut down the balancing control of the second balancing cell that needs to be turned on if the balancing control time of the second balancing cell that needs to be turned on is greater than the balancing time.

[0113] For the specific definition of the full-time balancing device of the battery, please refer to the definition of the full-time balancing method of the battery above, which will not be repeated here. Each module in the full-time balancing device of the battery can be implemented in whole or in part by software, hardware and a combination thereof. The above modules can be embedded in or independent of the processor in the controller in the form of hardware, or can be stored in the memory in the controller in the form of software, so that the processor can call and execute the operations corresponding to the above modules.

[0114] Fig.12 This is a schematic diagram of the structure of a controller provided in Embodiment 9 of the present invention. Fig.12 As shown, the controller of this embodiment includes: at least one processor ( Fig.12 Only one is shown), a memory, and a computer program stored in the memory and executable on at least one processor, wherein when the processor executes the computer program, the steps of any of the above-mentioned full-time balancing method embodiments of each battery are implemented.

[0115] The controller may include, but is not limited to, a processor and a memory. A person skilled in the art will understand that Fig.12 This is merely an example of a controller and does not constitute a limitation of the controller. The controller may include more or fewer components than shown in the figure, or a combination of certain components, or different components. For example, it may also include a network interface, a display screen, and an input device.

[0116] The processor may be a CPU, or other general-purpose processors, a digital signal processor (DSP), an application-specific integrated circuit (ASIC), a field-programmable gate array (FPGA) or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. A general-purpose processor may be a microprocessor or any conventional processor, etc.

[0117] The memory includes a readable storage medium, an internal memory, etc., wherein the internal memory may be the memory of the controller, and the internal memory provides an environment for the operation of the operating system and the computer-readable instructions in the readable storage medium. The readable storage medium may be the hard disk of the controller, and in other embodiments, it may also be an external storage device of the controller, for example, 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), etc. equipped on the controller. Further, the memory may also include both an internal storage unit of the controller and an external storage device. The memory is used to store an operating system, an application program, a boot loader (BootLoader), data, and other programs, such as the program code of a computer program, etc. The memory may also be used to temporarily store data that has been output or is to be output.

[0118] The technicians in the relevant field can clearly understand that for the convenience and simplicity of description, only the division of the above-mentioned functional units and modules is used as an example. In practical applications, the above-mentioned function allocation can be completed by different functional units and modules as needed, that is, the internal structure of the device is divided into different functional units or modules to complete all or part of the functions described above. The functional units and modules in the embodiment can be integrated into a processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit. The above-mentioned integrated unit can be implemented in the form of hardware or in the form of software functional units. In addition, the specific names of the functional units and modules are only for the convenience of distinguishing each other, and are not used to limit the scope of protection of the present invention. The specific working process of the units and modules in the above-mentioned device can refer to the corresponding process in the above-mentioned method embodiment, which will not be repeated here. If the integrated unit is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on such understanding, the present invention implements all or part of the processes in the above-mentioned embodiment method, which can be completed by instructing the relevant hardware through a computer program, and the computer program can be stored in a computer-readable storage medium. When the computer program is executed by the processor, the steps of the above-mentioned method embodiment can be implemented. Among them, the computer program includes computer program code, and the computer program code can be in source code form, object code form, executable file or some intermediate form. The computer-readable medium may at least include: any entity or device capable of carrying computer program code, recording medium, computer memory, read-only memory (ROM), random access memory (RAM), electric carrier signal, telecommunication signal and software distribution medium. For example, a USB flash drive, a mobile hard disk, a magnetic disk or an optical disk. In some jurisdictions, according to legislation and patent practice, computer-readable media cannot be electric carrier signals and telecommunication signals.

[0119] The present invention implements all or part of the processes in the above-mentioned method embodiment, and can also be completed by a computer program product. When the computer program product runs on a controller, the controller can implement the steps in the above-mentioned method embodiment when executing.

[0120] In the above embodiments, the description of each embodiment has its own emphasis. For parts that are not described or recorded in detail in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0121] Those skilled in the art will appreciate that the units and algorithm steps of each example described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Professional and technical personnel can use different methods to implement the described functions for each specific application, but such implementation should not be considered to be beyond the scope of the present invention.

[0122] In the embodiments provided by the present invention, it should be understood that the disclosed devices / controllers and methods can be implemented in other ways. For example, the device / controller embodiments described above are only schematic, for example, the division of modules or units is only a logical function division, and there may be other division methods in actual implementation, such as multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some interfaces, indirect coupling or communication connection of devices or units, which can be electrical, mechanical or other forms.

[0123] The units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed on multiple network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0124] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that the technical solutions described in the aforementioned embodiments may still be modified, or some of the technical features may be replaced by equivalents. Such modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention, and should be included in the protection scope of the present invention.

Claims

1. A full-time balancing method for a battery, characterized in that: The full-time balancing method comprises the following steps: When the battery is in the charging stage, the voltage of each single cell in the battery is collected in real time, and if the voltages of all the single cells in the battery meet the first balancing condition, the single cells of the battery are balanced by using voltage difference balancing; When the battery is in a resting stage after being fully charged, the capacity of each single cell in the battery is estimated, and if the capacity of all single cells in the battery meets a second balancing condition, the single cells of the battery are balanced by using capacity difference balancing.

2. The full-time balancing method for a battery as claimed in claim 1, characterized in that: If the voltages of all the single cells meet the first balancing condition, the single cells of the battery are balanced by using voltage difference balancing, including: Determining the highest cell voltage and the lowest cell voltage from the voltages of all the cells in the battery; If the highest cell voltage is greater than the first voltage value, detecting whether the voltage difference between the highest cell voltage and the lowest cell voltage is greater than a second voltage value; If it is detected that the voltage difference is greater than the second voltage value, it is determined that the voltages of all the single cells in the battery meet the first balancing condition, and the voltage difference balancing is used to perform balancing control on the single cells of the battery.

3. The full-time balancing method for a battery as claimed in claim 1, characterized in that: The method of using voltage difference balancing to balance the single cells of the battery includes: Calculating the average voltage of all single cells in the battery, and for any single cell in the battery, if the voltage of the single cell is greater than the average voltage, and the voltage difference between the voltage of the single cell and the lowest single cell voltage is greater than the second voltage value, then the single cell is defined as the first cell that needs to be equalized; Divide all first balancing cells that need to be turned on into two groups, wherein two adjacent first balancing cells that need to be turned on are not in the same group; According to the preset first period, the balancing control of the two groups is periodically started.

4. The full-time balancing method for a battery as claimed in claim 3, characterized in that: After the balancing control of the two groups is periodically started according to the preset first period, the method further includes: For any first balancing cell that needs to be turned on, if the current voltage of the first balancing cell that needs to be turned on is lower than the voltages of other single cells in the battery, turning off the balancing control of the first balancing cell that needs to be turned on; The current voltage is used as a balancing stop voltage. If the voltage of any first balancing cell that needs to be turned on is lower than the balancing stop voltage, the balancing control of the corresponding first balancing cell that needs to be turned on is turned off.

5. The full-time balancing method for a battery as claimed in claim 1, characterized in that: Before the battery is in a resting stage after being fully charged, the method further comprises: Determining the highest single cell capacity from the capacities of all single cells in the battery; If the highest single cell capacity is greater than the first capacity value, detecting whether the charging current of the battery is less than the first current value; If it is detected that the charging current is less than the first current value, it is determined that the battery is in a fully charged state.

6. The full-time balancing method for a battery as claimed in claim 1, characterized in that: If the capacities of all the single cells in the battery meet the second balancing condition, the single cells of the battery are balanced by using capacity difference balancing, including: Determining the lowest single cell capacity from the capacities of all single cells in the battery; For any single cell in the battery, if the capacity difference between the single cell and the minimum single cell capacity is greater than a second capacity value, it is determined that the single cell meets the second balancing condition, and the single cell is set as a second balancing cell to be started; Divide all the second balancing cells that need to be turned on into two groups, wherein two adjacent second balancing cells that need to be turned on are not in the same group; According to the preset second period, the balancing control of the two groups is periodically started.

7. The full-time balancing method for a battery as claimed in claim 6, characterized in that: After the balancing control of the two groups is periodically started according to the preset second period, the method further includes: For any second balancing cell that needs to be turned on, calculating the balancing time of the second balancing cell that needs to be turned on according to a preset balancing current; If the time of the balancing control on the second balancing cell that needs to be turned on is greater than the balancing time, the balancing control on the second balancing cell that needs to be turned on is turned off.

8. A full-time balancing device for a battery, characterized in that: The full-time balancing device comprises: A voltage difference balancing module is used to collect the voltage of each single cell in the battery in real time when the battery is in a charging stage, and if the voltage of all the single cells in the battery meets a first balancing condition, use voltage difference balancing to perform balancing control on the single cells of the battery; The capacity difference balancing module is used to estimate the capacity of each single cell in the battery when the battery is in a static stage after being fully charged, and if the capacity of all the single cells in the battery meets the second balancing condition, use capacity difference balancing to balance the single cells of the battery.

9. A controller comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that: When the processor executes the computer program, the steps of the full-time balancing method for a battery as claimed in any one of claims 1 to 7 are implemented.

10. A battery, characterized in that: It comprises a battery cell and a controller as claimed in claim 9.

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