Electric quantity equalization method for lithium battery pack

Abstract

The invention discloses an electric quantity balancing method for a lithium battery pack. According to the invention, through a built-in calculation model, average calculation is carried out on the obtained voltage data of all the battery monomers, the calculated average value is compared with the voltage data of the battery monomers, and locking marking is carried out on the battery monomers of which the voltage difference value is greater than 0.5 V; then, the electric quantity of the high-voltage single battery with the positive difference value is transferred to the electric quantity of the low-voltage single battery with the negative difference value to realize active equalization, and all the single batteries are continuously balanced in real time through repeated monitoring, calculation and comparison; and when the voltage difference between the voltage value of the single battery and the average voltage value is smaller than an initial threshold value 0.5 V, the equalization operation is ended, so that the device has the advantages of realizing calculation model updating in the later period, adapting to battery data change, improving calculation precision and equalization effect and prolonging the service life of the battery along with the increase of the service time of the battery.

Description

Technical Field

[0001] This invention relates to the field of lithium battery power balancing technology, and more specifically, to a power balancing method for lithium battery packs. Background Technology

[0002] In recent years, due to the advantages of lithium-ion batteries such as small size, high energy density, no memory effect, long cycle life, and low self-discharge rate, more and more products have adopted lithium-ion batteries as the main power source. However, lithium-ion batteries have very high requirements for charging and discharging. When overcharging, over-discharging, overcurrent, or short circuits occur, the pressure and heat of the lithium-ion battery increase significantly, which can easily cause sparks, combustion, or even explosion. Therefore, equalization measures are taken to protect lithium-ion batteries from overcharging and over-discharging during the charging and discharging of a group of lithium-ion batteries, in order to ensure the consistency of the voltage of each individual cell.

[0003] Current active balancing methods achieve battery voltage balance by transferring the charge from high-voltage cells to low-voltage cells. However, in actual use, the voltage and charge data of the battery will change over time. The current active balancing method lacks the ability to adapt to changes in battery data in the later stages of battery use, resulting in poor balancing effect and a shorter overall battery life. Summary of the Invention

[0004] In view of the problems existing in the prior art, the purpose of this invention is to provide a power balancing method for lithium battery packs to solve the problems in the background art.

[0005] To achieve the above objectives, the present invention adopts the following technical solution;

[0006] A method for equalizing the charge of a lithium battery pack, characterized by comprising the following steps:

[0007] S1. First, obtain the voltage data of all individual cells in the battery pack.

[0008] S2, with a built-in calculation model, calculates the average voltage value.

[0009] S3. Compare the average voltage value and identify battery cells whose voltage difference with the average voltage is greater than 0.5V.

[0010] When the voltage difference is below 0.5V, proceed to step S5 to monitor voltage data; when the voltage difference is above 0.5V, proceed to the next step.

[0011] S4. Depressurize the cells with voltages higher than the average voltage to the cells with voltages lower than the average voltage.

[0012] S5. Repeat S1 until the voltage data of all battery cells are detected, and the voltage difference between the voltage value of all battery cells and the average voltage value is less than 0.5V, then end.

[0013] As a further description of the above technical solution: the built-in calculation model data in step S2 can be periodically transmitted to the database and updated through AI learning. As the data of the individual battery cells changes, the calculation model is updated accordingly.

[0014] As a further description of the above technical solution: each of the battery cells is synchronously connected in parallel with a power transfer unit, and the power transfer unit can perform independent charging and discharging operations on the battery cells.

[0015] As a further description of the above technical solution: during the charging process, the power transfer unit only performs a discharge operation on the individual battery cells.

[0016] As a further description of the above technical solution: when step S3 is executed repeatedly, battery cells that frequently experience pressure differences exceeding the threshold are marked and an isolation procedure is set.

[0017] As a further description of the above technical solution: the power inside the power transfer unit 3 is consumed first, and the power inside the power transfer unit is set to a minimum level. When the power is consumed to the minimum level, the consumption stops.

[0018] As a further description of the above technical solution: when step S1 is performed, the data for the marked and isolated battery cells is not included.

[0019] As a further description of the above technical solution: the initial differential pressure value in step S3 is 0.5V by default, which can be preset according to different battery materials, and can be adaptively adjusted according to the calculation model data after the battery usage data changes.

[0020] Compared with the prior art, the advantages of this invention are:

[0021] This solution enables synchronous AI training by setting up a computational model and accessing external big data, providing a more accurate computational model for batteries in later stages of use, ensuring computational accuracy and balancing performance.

[0022] This solution utilizes a power transfer unit to balance the flow of power, thereby improving balancing efficiency and enabling efficient, multiple real-time balancing. Simultaneously, it can provide auxiliary voltage boosting for battery cells with insufficient voltage during charging, improving charging efficiency, reducing the balancing process during charging, increasing charging speed, and reducing charging time at the end of the charging process. Attached Figure Description

[0023] Figure 1 This is a front view structural diagram of the present invention;

[0024] Figure 2 This is a schematic diagram of the operating structure of the present invention.

[0025] Explanation of the labels in the diagram:

[0026] 1. Battery pack; 2. Battery cell; 3. Power transfer unit. Detailed Implementation

[0027] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention;

[0028] Please see Figures 1-2 In this invention, a method for equalizing the charge of a lithium battery pack includes the following steps:

[0029] S1. First, obtain the voltage data of all individual battery cells 2 in battery pack 1.

[0030] S2, with a built-in calculation model, calculates the average voltage value.

[0031] S3. Compare the average voltage value and lock in the battery cell 2 whose voltage difference with the average voltage is greater than 0.5V.

[0032] When the voltage difference is below 0.5V, proceed to step S5 to monitor voltage data; when the voltage difference is above 0.5V, proceed to the next step.

[0033] S4. Depressurize the cells with voltages higher than the average voltage to the cells with voltages lower than the average voltage.

[0034] S5. Repeat S1 until the voltage data of all battery cells are detected, and the voltage difference between the voltage value of all battery cells 2 and the average voltage value is less than 0.5V, then end.

[0035] In this invention, a built-in calculation model is used to average the voltage data of all acquired battery cells 2. The calculated average value is compared with the voltage data of battery cells 2, and battery cells 2 with a voltage difference greater than 0.5V are marked as locked. Active balancing is achieved by transferring the charge from high-voltage battery cells 2 with positive voltage differences to low-voltage battery cells 2 with negative voltage differences. Through repeated monitoring, calculation, and comparison, continuous real-time balancing of all battery cells 2 is achieved until the voltage difference between the voltage value of a battery cell 2 and the average voltage value is less than the initial threshold of 0.5V. At this point, the balancing operation ends, and only the voltage value acquisition and average value calculation of battery cells 2 are performed. The process continues until the difference between the average value and the voltage difference of battery cells 2 again exceeds the initial threshold. After reaching 0.5V, a balancing operation is performed again. As the battery cell 2 is used for a longer period of time, the calculation model is automatically updated to improve calculation accuracy and ensure balancing effect. This allows the device to update the calculation model as the battery usage time increases, adapt to changes in battery data, improve calculation accuracy and balancing effect, and extend battery life. This solves the problem in the existing technology that achieves battery voltage balancing by transferring the charge from the high-voltage cell to the low-voltage cell. However, in actual use, the voltage and charge data of the battery will change as the usage time increases. The current active balancing method lacks adaptive adjustment to changes in battery data in the later stages of battery use, resulting in poor balancing effect and shortened overall battery life.

[0036] Please see Figure 2 In step S2, the built-in calculation model data can be periodically transmitted to the database and updated for AI learning. As the data of battery cell 2 changes, the calculation model is updated accordingly.

[0037] In this invention, the built-in computing model data can be periodically transmitted to the database and updated through AI learning. As the data of the battery cell 2 changes in the later stages of use, the model can be adaptively adjusted to achieve data networking, improve computing accuracy, and ensure the balancing effect.

[0038] Please see Figure 1 In this configuration, each battery cell 2 is connected in parallel to a power transfer unit 3, which can perform independent charging and discharging operations on each battery cell 2.

[0039] In this invention, by setting up a power transfer unit 3 to realize the power transfer between battery cells 2, the power balancing can be achieved more efficiently and accurately, and the efficiency of single power balancing can be improved.

[0040] Please see Figure 2 Among them, the power transfer unit 3 only performs a discharge operation on the individual battery 2 during the charging process.

[0041] In this invention, the power transfer unit 3 performs a boosting operation on a few battery cells 2 whose power is lower than the average voltage during the charging process, thereby increasing the overall charging speed, reducing the number of repeated equalization operations in the later stages of charging, and reducing the charging time.

[0042] Please see Figure 2 In step S3, when the battery cell 2 that frequently experiences a pressure difference exceeding the threshold is marked and an isolation procedure is set.

[0043] In this invention, by marking and isolating battery cells 2 that frequently experience voltage differences exceeding the threshold, the risk of damage to the battery pack 1 is effectively reduced, and the impact on battery output is minimized, thereby improving safety.

[0044] Please see Figure 2 Among them, the power inside the power transfer unit 3 is consumed first, and the power inside the power transfer unit 3 is set to a minimum level. When the power is consumed to the minimum level, the consumption stops.

[0045] In this invention, by limiting the power consumption of the power transfer unit 3, it is ensured that it has sufficient capacity to discharge the high-voltage battery cell 2, and a minimum value is set to avoid the power transfer unit 3 being depleted, ensuring that the output boost operation can be performed at any time.

[0046] Please see Figure 2 Wherein: when step S1 is executed, the data for the marked and isolated battery cell 2 is not included.

[0047] In this invention, the data of the marked and isolated battery cells 2 are not included during step S1 to ensure the accuracy of subsequent calculations and the balancing effect.

[0048] Please see Figure 2 The initial differential pressure value in step S3 is 0.5V by default. It can be preset according to different battery materials and adaptively adjusted according to the calculation model data as the battery usage data changes.

[0049] In this invention, by accessing external big data through a computational model and updating it in a timely manner, and by adopting an adaptive computational model based on the data change cycle of battery cell 2, the computational accuracy in the later stages of battery use is improved, ensuring the balancing effect and extending battery life.

[0050] The above description is merely a preferred embodiment of the present invention; however, the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and its improved concepts, should be covered within the scope of protection of the present invention.

Claims

1. A method for equalizing the charge of a lithium battery pack, characterized in that, Includes the following steps: S1. First, obtain the voltage data of all battery cells (2) in the battery pack (1); S2. Built-in calculation model, and calculates the average voltage value; S3. Compare the average voltage value and lock the battery cell with a voltage difference greater than 0.5V from the average voltage value (2); Specifically, when the voltage difference is below 0.5V, proceed to step S5 to monitor voltage data; when the voltage difference is above 0.5V, proceed to the next step. S4. Depressurize and balance the battery cells with voltages higher than the average voltage to the battery cells with voltages lower than the average voltage. S5. Repeat S1 until the voltage data of all battery cells are detected and the voltage difference between the voltage value of all battery cells (2) and the average voltage value is less than 0.5V, then end.

2. The method for equalizing the charge of a lithium battery pack according to claim 1, characterized in that: In step S2, the built-in calculation model data can be periodically transmitted to the database and updated through AI learning. As the data of the battery cell 2 changes, the calculation model is updated accordingly.

3. The method for equalizing the charge of a lithium battery pack according to claim 2, characterized in that: Each battery cell (2) is connected in parallel with a power transfer unit (3), and the power transfer unit (3) can perform independent charging and discharging operations on the battery cell (2).

4. A method for equalizing the charge of a lithium battery pack according to claim 2, characterized in that: During the charging process, the power transfer unit (3) only discharges the individual battery (2).

5. A method for equalizing the charge of a lithium battery pack according to claim 1, characterized in that: When step S3 is executed repeatedly, battery cells 2 that frequently experience pressure differences exceeding the threshold are marked and an isolation procedure is set.

6. A method for equalizing the charge of a lithium battery pack according to claim 4, characterized in that: The power in the power transfer unit (3) is consumed first, and the power in the power transfer unit (3) is set to a minimum level. When the power is consumed to the minimum level, the consumption stops.

7. A method for equalizing the charge of a lithium battery pack according to claim 5, characterized in that: When step S1 is performed, the data for the marked and isolated battery cells 2 is not included.

8. A method for equalizing the charge of a lithium battery pack according to claim 2, characterized in that: The initial differential pressure value in step S3 is 0.5V by default. It can be preset according to different battery materials and adaptively adjusted according to the calculation model data as the battery usage data changes.

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