Battery equalization system

Abstract

According to the battery equalization system provided by the invention, the single battery control unit controls the single battery charging unit and the single battery discharging unit according to the voltage data so as to realize charging or discharging control on the single batteries, so that charging or discharging equalization control on the battery pack is realized, the equalization efficiency can be improved, and the equalization time can be shortened.

Description

Technical Field

[0001] The present application relates to the field of battery management technology, and in particular to a battery balancing system. Background Art

[0002] After repeated use, the battery pack may experience large voltage differences between cells.

[0003] Cell imbalance can cause the following damage to cells and battery packs:

[0004] 1. Safety hazards: Battery imbalance can easily lead to overcharging and over-discharging. Overcharging and over-discharging can generate heat and chemical reactions in the battery, leading to safety issues such as battery short circuit, overheating, and even explosion.

[0005] 2. Shortened lifespan: Battery imbalance will cause certain batteries to have a greater load, which may shorten the lifespan of these batteries and thus affect the lifespan of the battery pack.

[0006] 3. Performance degradation: Battery imbalance will cause the total voltage and capacity of the battery pack to decrease, thereby affecting the performance of the battery pack, such as battery pack output power and driving range.

[0007] Therefore, the batteries need to be balanced. How to balance the batteries has become a technical problem that needs to be solved urgently. Summary of the Invention

[0008] The purpose of the embodiments of the present application is to provide a battery balancing system to solve the above technical problems.

[0009] A battery balancing system, comprising:

[0010] A battery pack consisting of a plurality of single cells and a single cell management module respectively provided for each of the single cells, each of the single cell management modules comprising a single cell sampling unit, a single cell charging unit, a single cell discharging unit and a single cell control unit;

[0011] The single cell sampling unit is used to collect voltage data of the single cell;

[0012] The single cell control unit is used to control the single cell charging unit and the single cell discharging unit according to the voltage data, so as to charge or discharge the single cell.

[0013] In one embodiment, the single cell battery control unit is used to determine whether the starting voltage value of the single cell battery is a low voltage when the absolute value of the voltage difference between the starting voltage value of the single cell battery and the first preset voltage value is greater than the first preset voltage difference threshold; if so, control the single cell battery charging unit to charge the single cell battery; if not, control the single cell battery discharging unit to discharge the single cell battery.

[0014] In one embodiment, the single cell battery control unit is used to determine that the starting voltage value is a low voltage when the starting voltage value is less than or equal to a second preset voltage value, and is used to determine that the starting voltage value is a high voltage when the starting voltage value is greater than the second preset voltage value.

[0015] In one embodiment, the single cell control unit is configured to, when the absolute value of the voltage difference between the starting voltage values ​​of each single cell is less than a second preset voltage difference threshold, control the single cell charging unit to charge the single cell if it is determined that the starting voltage value of the single cell is less than a third preset voltage value; and control the single cell discharging unit to discharge the single cell if it is determined that the starting voltage value of the single cell is greater than the third preset voltage value.

[0016] In one embodiment, the third preset voltage value is the rated voltage of the single battery.

[0017] In one embodiment, the single cell battery management module further includes an auxiliary power supply unit and an isolated power supply unit; the auxiliary power supply unit is used to supply power to the single cell battery sampling unit, the single cell battery discharging unit and the single cell battery control unit; the isolated power supply unit is used to supply power to the battery charging unit.

[0018] In one embodiment, the battery balancing system further includes a battery sampling module, a battery charging module, a battery discharging module, and a main control module; the battery sampling module is used to collect working data of the battery pack; the main control module is used to control the battery charging module and the battery discharging module according to the working data to achieve control of the charging process or the discharging process of the battery pack;

[0019] Each of the single battery management modules further includes a communication unit, and the communication unit is used to communicate with the main control module.

[0020] In one embodiment, the first communication unit is configured to communicate with the main control module via an RS485 bus.

[0021] In one embodiment, the battery balancing system further includes a communication module, and the communication module is used to implement external communication.

[0022] In one embodiment, the battery balancing system further includes a display module, and the display module is used to implement a human-computer interaction function of the battery balancing system.

[0023] Through the battery balancing system provided in the present application, the single cell control unit controls the single cell charging unit and the single cell discharging unit according to the voltage data to realize the charging or discharging control of the single cell, thereby realizing the charging or discharging balancing control of the battery pack, which can improve the balancing efficiency and shorten the balancing time. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 A schematic diagram of the structure of a battery balancing system provided in an embodiment of the present application;

[0025] Figure 2 A first structural diagram of a single battery management module provided in an embodiment of the present application;

[0026] Figure 3 A block diagram of the battery balancing system provided in an embodiment of the present application;

[0027] Figure 4 This is a second structural diagram of the single cell battery management module provided in an embodiment of the present application. DETAILED DESCRIPTION

[0028] In order to make the purpose, technical solutions and advantages of this application more clear, the following further describes this application in detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain this application and are not intended to limit this application.

[0029] This application embodiment provides a battery balancing system, see Figure 1 、 Figure 2 and Figure 3 Shown, including:

[0030] A battery pack consisting of a plurality of single cells and a single cell management module 1 respectively provided for each of the single cells, each of the single cell management modules comprising a single cell sampling unit 11, a single cell charging unit 12, a single cell discharging unit 13 and a single cell control unit 14;

[0031] The single cell sampling unit 11 is used to collect voltage data of the single cell;

[0032] The single cell control unit 14 is used to control the single cell charging unit 12 and the single cell discharging unit 13 according to the voltage data, so as to charge or discharge the single cell.

[0033] In the embodiment of the present application, the battery pack can be a lithium-ion battery pack, which is composed of multiple lithium-ion single cells. Each lithium-ion single cell can be connected in series. Each lithium-ion single cell is provided with its corresponding single cell management module 1. Each single cell management module 1 jointly realizes the single cell voltage collection and hybrid balancing function of the lithium-ion battery pack.

[0034] The battery balancing system in the embodiment of the present application may further include a battery pack sampling module 2, a battery pack charging module 3, a battery pack discharging module 4 and a main control module 5; the battery pack sampling module 2 is used to collect operating data of the battery pack; the main control module 5 is used to control the battery pack charging module 3 and the battery pack discharging module 4 according to the operating data to achieve control of the battery pack charging process or discharging process; each of the single battery management modules 1 may further include a communication unit 15, which is used to communicate with the main control module.

[0035] The communication unit can communicate with the main control module via an RS485 bus.

[0036] Specifically, the battery pack sampling module 2 can collect information such as the battery pack's full charge / discharge current and system temperature. The main control module 5 can analyze the voltage, charge and discharge current and other data of each single battery received in real time, control the charging or discharging process as needed, determine whether the battery pack has abnormal conditions such as overcharging or over-discharging, and send this information to the host computer system.

[0037] The single cell battery control unit 14 in the embodiment of the present application is used to determine whether the starting voltage value of the single cell battery is a low voltage when the absolute value of the voltage difference between the starting voltage value of the single cell battery and the first preset voltage value is greater than the first preset voltage difference threshold. If so, control the single cell battery charging unit to charge the single cell battery; if not, control the single cell battery discharging unit to discharge the single cell battery.

[0038] The single cell control unit 14 in the embodiment of the present application can determine that the starting voltage value is a low voltage when the starting voltage value is less than or equal to a second preset voltage value, and can be used to determine that the starting voltage value is a high voltage when the starting voltage value is greater than the second preset voltage value.

[0039] The single cell control unit is further configured to, when the absolute value of the voltage difference between the starting voltage values ​​of the single cells is less than a second preset voltage difference threshold, control the single cell charging unit to charge the single cell if it is determined that the starting voltage value of the single cell is less than a third preset voltage value; and control the single cell discharging unit to discharge the single cell if it is determined that the starting voltage value of the single cell is greater than the third preset voltage value.

[0040] In the embodiment of the present application, the first preset voltage value, the first preset voltage difference threshold, the second preset voltage value, the second preset voltage difference threshold and the third preset voltage value can be flexibly set by the developer or the user. For example, the first preset voltage difference threshold can be set to 0.5V, and the third preset voltage value can be the rated voltage of the single cell.

[0041] The single cell management module in the embodiment of the present application may further include an auxiliary power supply unit 16 and an isolated power supply unit 17; the auxiliary power supply unit is used to supply power to the single cell sampling unit 11, the single cell discharge unit 13 and the single cell control unit 14; the isolated power supply unit is used to supply power to the battery charging unit 12.

[0042] It should be noted that the auxiliary power supply unit 16 can provide 3.3V operating voltage to the single cell sampling unit 11, the single cell discharging unit 13 and the single cell control unit 14, and the isolated power supply unit 17 can provide system power to the battery charging unit.

[0043] The battery balancing system may further include a communication module 6 , which is used to implement external communication.

[0044] The battery balancing system may further include a display module 7 , which is used to implement a human-computer interaction function of the battery balancing system.

[0045] See Figure 4 As shown, for each battery cell, an independent small system can be used for management, including voltage monitoring, balancing (active and passive hybrid mode), communication control, etc.

[0046] This small system uses a 16-bit high-precision ADC for sampling. Before the system operates, it discharges a single battery cell with a high instantaneous current to collect the voltage value at the moment of discharge. Based on ΔV / I=ΔR, it calculates the sum of the line loss and internal resistance, which is used as a parameter correction in subsequent balanced sampling.

[0047] According to the initial condition of the battery pack, the single-cell balancing strategy is divided into coarse adjustment and fine adjustment. During coarse adjustment, the median of the battery pack single-cell voltage is used as the reference point. If it is above the reference point, constant current discharge passive balancing is adopted, and if it is below the reference point, charging active balancing is adopted. The current of both balancing methods is adjustable. When the voltage of each single cell is not much different, passive or active balancing is selected according to the stage. If the charging is close to completion, passive balancing is adopted to prevent overcharging. If it is the initial charging stage, charging active balancing is adopted to prevent over-discharge.

[0048] It should be noted that the diagrams provided in this embodiment are only used to illustrate the basic concept of the present invention. Therefore, the diagrams only show the components related to the present invention and are not drawn according to the number, shape and size of the components in actual implementation. The type, quantity and proportion of each component in actual implementation can be changed at will, and the component layout type may also be more complex. The structures, proportions, sizes, etc. shown in the drawings of this specification are only used to match the content disclosed in the specification for people familiar with this technology to understand and read. They are not used to limit the conditions for the implementation of the present invention, so they have no technical significance. Any modification of the structure, change of the proportional relationship or adjustment of the size should still fall within the scope of the technical content disclosed in the present invention without affecting the effect and purpose that can be achieved by the present invention. At the same time, the terms such as "upper", "lower", "left", "right", "middle" and "one" quoted in this specification are only for the convenience of description and are not used to limit the scope of implementation of the present invention. Changes or adjustments to their relative relationships should also be regarded as the scope of implementation of the present invention without substantially changing the technical content.

[0049] The technical features of the above embodiments can be combined arbitrarily. To make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0050] The above-described embodiments merely represent several implementation methods of the present application. While the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the present invention. It should be noted that a person skilled in the art could make various modifications and improvements without departing from the spirit of the present application, all of which fall within the scope of protection of the present application. Therefore, the scope of protection of the present patent application shall be determined by the appended claims.

Claims

1. A battery balancing system, characterized in that: include: A battery pack consisting of a plurality of single cells and a single cell management module respectively provided for each of the single cells, each of the single cell management modules comprising a single cell sampling unit, a single cell charging unit, a single cell discharging unit and a single cell control unit; The single cell sampling unit is used to collect voltage data of the single cell; The single cell control unit is used to control the single cell charging unit and the single cell discharging unit according to the voltage data, so as to charge or discharge the single cell.

2. The battery balancing system according to claim 1, wherein: The single cell control unit is used to determine whether the starting voltage value of the single cell is a low voltage when the absolute value of the voltage difference between the starting voltage value of the single cell and the first preset voltage value is greater than the first preset voltage difference threshold; if so, control the single cell charging unit to charge the single cell; if not, control the single cell discharging unit to discharge the single cell.

3. The battery balancing system according to claim 2, wherein: The single cell control unit is used to determine that the starting voltage value is a low voltage when the starting voltage value is less than or equal to a second preset voltage value, and is used to determine that the starting voltage value is a high voltage when the starting voltage value is greater than the second preset voltage value.

4. The battery balancing system according to claim 1, wherein: The single cell control unit is configured to, when the absolute value of the voltage difference between the starting voltage values ​​of the single cells is less than a second preset voltage difference threshold, control the single cell charging unit to charge the single cell if it is determined that the starting voltage value of the single cell is less than a third preset voltage value; and control the single cell discharging unit to discharge the single cell if it is determined that the starting voltage value of the single cell is greater than the third preset voltage value.

5. The battery balancing system according to claim 4, wherein: The third preset voltage value is the rated voltage of the single battery.

6. The battery balancing system according to claim 1, wherein: The single cell management module further includes an auxiliary power supply unit and an isolation power supply unit; the auxiliary power supply unit is used to supply power to the single cell sampling unit, the single cell discharge unit and the single cell control unit; The isolated power supply unit is used to supply power to the battery charging unit.

7. The battery balancing system according to claim 1, wherein: The battery balancing system further includes a battery sampling module, a battery charging module, a battery discharging module, and a main control module; the battery sampling module is used to collect operating data of the battery pack; the main control module is used to control the battery charging module and the battery discharging module according to the operating data to achieve control of the battery pack charging process or discharging process; Each of the single battery management modules further includes a communication unit, and the communication unit is used to communicate with the main control module.

8. The battery balancing system according to claim 7, wherein: The communication unit is used to communicate with the main control module via the RS485 bus.

9. The battery balancing system according to claim 7, wherein: The battery balancing system further includes a communication module, and the communication module is used to implement external communication.

10. The battery balancing system according to claim 7, wherein: The battery balancing system further includes a display module, which is used to implement a human-computer interaction function of the battery balancing system.

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