Concentrated charging system for lithium batteries with different SOC (State of Charge)

Abstract

The utility model provides a centralized charging system for different SOC lithium batteries. The centralized charging system comprises a plurality of battery modules, the charging module is sequentially connected with the plurality of battery modules through a power wire harness; and the plurality of combined contactors are arranged on the power wire harness, and each combined contactor controls connection and disconnection between one battery module and the charging module. Each battery module is provided with a combined contactor, so that the fully-charged battery module can be cut out from a main loop where the charging module is connected with the battery module, and accurate charging of a plurality of lithium battery packs with relatively large SOC difference is realized; according to the invention, concentrated charging is realized, the lithium batteries do not need to be grouped according to the SOC, the complexity of the charging process is not increased while the problems of easy over-charging and over-discharging and low safety existing in lithium battery charging in the prior art can be solved, the safety and reliability of the charging process are ensured, the charging efficiency and the battery performance are improved, and the service life of the battery is prolonged; and the charging cost is reduced.

Description

Technical Field

[0001] This utility model relates to the field of battery management technology, specifically to a centralized charging system for lithium batteries with different SOCs. Background Technology

[0002] Lithium-ion batteries are widely used as important energy storage components in electric vehicles, energy storage power stations, and renewable energy systems. However, due to factors such as usage conditions, charging and discharging strategies, and individual differences, lithium-ion batteries from the same or different batches often exhibit different states of charge (SOC). Traditional charging methods often ignore this difference and adopt a uniform charging strategy, such as constant current charging, constant voltage charging, or constant current constant voltage charging. This method is simple and easy to implement, and does not require individual management of batteries. However, due to the difference in SOC between batteries, some batteries may be overcharged or over-discharged, affecting battery performance and safety.

[0003] Currently, some charging methods take into account the battery's State of Charge (SOC). For example, batch charging groups batteries based on their SOC and then charges them separately. Typically, batteries with similar SOCs are grouped together and charged using the same charging strategy. Compared to uniform charging, this method reduces the impact of SOC differences between batteries on charging performance, but it requires additional grouping and management operations, increasing the complexity of the charging process.

[0004] Therefore, it is necessary to design a centralized charging system for lithium batteries with different SOCs that can solve the problems of easy overcharging and over-discharging and low safety in existing lithium battery charging technologies without increasing the complexity of the charging process. Utility Model Content

[0005] The purpose of this invention is to overcome the shortcomings of the prior art and provide a centralized charging system for lithium batteries with different SOCs. This system can solve the problems of easy overcharging and over-discharging and low safety in the existing lithium battery charging technology without increasing the complexity of the charging process.

[0006] To achieve the above and other objectives, this utility model is implemented through the following technical solution: This utility model proposes a centralized charging system for lithium batteries with different SOCs, including multiple battery modules; a charging module, which is sequentially connected to the multiple battery modules through a power harness; and multiple combination contactors, which are disposed on the power harness, with each combination contactor controlling the connection and disconnection between one battery module and the charging module.

[0007] In one embodiment, the combined contactor includes three DC contactors; two of which are branch contactors, respectively disposed at both ends of the battery module, and one is a main circuit contactor, disposed on the main circuit of the charging module, located between the two branch contactors.

[0008] In one embodiment, the charging module is a 1500V high-voltage charging module.

[0009] In one embodiment, the centralized charging system for lithium batteries with different SOCs further includes a BMS module, which is connected to the battery module via a communication harness and is used to monitor and collect the status of individual cells in the battery module.

[0010] In one embodiment, the centralized charging system for lithium batteries with different SOCs further includes a centralized control module, which is connected to the charging module and the BMS module via communication harnesses.

[0011] In one embodiment, the BMS module includes a BMS slave controller and a BMS master controller; each battery module is equipped with one BMS slave controller; the BMS master controller is connected to the centralized control module and the multiple BMS slave controllers via a communication harness.

[0012] In one embodiment, the BMS slave controller can simultaneously support up to 8 of the battery modules online, with a total voltage ≤1500V.

[0013] In one embodiment, the centralized control module controls the output of the charging module via CAN or RS485 communication based on the individual battery status of all the battery modules, so as to charge all the battery modules with a constant current at a specified current.

[0014] In one embodiment, when the voltage of a single cell in any of the battery modules reaches a specified charging cutoff voltage, the centralized control module controls the charging module to stop charging. After a delay of 10s to 20s, the module controls the combined contactor of the corresponding fully charged battery module to disconnect the fully charged battery module.

[0015] In one embodiment, after a fully charged battery module is disconnected, after a delay of 30 seconds, the centralized control module controls the charging module to perform constant current charging on the remaining battery modules again.

[0016] Compared with the prior art, the beneficial effects of this utility model are as follows:

[0017] 1. This utility model, by equipping each battery module with a combined contactor, enables the fully charged battery module to be disconnected from the main circuit connecting the charging module and the battery module, achieving precise charging of multiple lithium battery packs with large differences in SOC. It achieves centralized charging without the need to group lithium batteries according to SOC, which solves the problems of easy overcharging and over-discharging and low safety in the existing lithium battery charging technology, without increasing the complexity of the charging process. It ensures the safety and reliability of the charging process, improves charging efficiency and battery performance, extends battery life, and reduces charging costs.

[0018] 2. The combined contactor of this utility model has a simple structure and is easy to operate. It can interlock the three contactors and switch out a fully charged battery module, which reduces the occupation of charging channel resources and lowers maintenance and operating costs.

[0019] 3. The design of the BMS module of this utility model can realize the accurate collection of status information of each battery module, improve the accuracy of power replenishment detection and control, and realize the accurate power replenishment of lithium batteries with different SOCs.

[0020] 4. This utility model incorporates an appropriate delay when switching off the fully charged battery module and resuming charging the remaining battery module during the power replenishment process, which ensures the safety and reliability of the power replenishment process. Attached Figure Description

[0021] Figure 1 The diagram shown is a structural schematic of a centralized charging system for lithium batteries with different SOCs according to this utility model. Detailed Implementation

[0022] Please see Figure 1 The following specific examples illustrate the implementation of this utility model. Those skilled in the art can easily understand other advantages and effects of this utility model from the content disclosed in this specification.

[0023] It should be noted that the structures, proportions, sizes, etc., illustrated in the accompanying drawings of this specification are only used to complement the content disclosed in the specification for those skilled in the art to understand and read, and are not intended to limit the conditions under which this utility model can be implemented. Therefore, they have no substantial technical significance. Any modifications to the structure, changes in the proportional relationships, or adjustments to the size, without affecting the effects and purposes that this utility model can produce, should still fall within the scope of the technical content disclosed in this utility model.

[0024] Unless otherwise defined, the technical or scientific terms used herein shall have the ordinary meaning as understood by one of ordinary skill in the art to which this invention pertains. The terms “a,” “an,” or “the,” as used herein, do not indicate a limitation of quantity, but are merely used to indicate the presence of at least one. Terms such as “comprising” or “including” mean that the element or object preceding the word encompasses the elements or objects listed following the word and their equivalents, without excluding other elements or objects. The term “connection” as used herein, unless otherwise specified, includes both direct and indirect connections.

[0025] To avoid confusion with this utility model, some technical features known in the art have not been described.

[0026] like Figure 1 As shown, this utility model provides a centralized charging system for lithium batteries with different SOCs, including a battery module 10, a charging module 20, a centralized control module 30, a battery management system (BMS) module 40, and a combined contactor 50. The battery module 10 includes multiple battery modules with different SOCs, which are connected in series during charging. The charging module 20 is a 1500V high-voltage charging module, connected to the multiple battery modules 10 via a power harness 60. The centralized control module 30 is connected to the charging module 20 and the BMS module 40 via a communication harness 70, and is responsible for receiving individual battery information data sent by the BMS module 40, controlling the charging module 20 to perform charging, and simultaneously controlling the combined contactor 50 to disconnect fully charged battery modules. The BMS module 40 includes a BMS slave controller and a BMS master controller. The BMS slave controller is used to monitor and collect the status information of individual battery cells. Each battery module 10 is equipped with an independent BMS slave controller, which can simultaneously support up to 8 battery modules 10 online, with a total system voltage ≤1500V. The BMS master controller is connected to the centralized control module 30 and multiple BMS slave controllers via a communication harness 70 for data communication between the battery modules 10 and the centralized control module 30. The combined contactor 50 is installed on the power harness 60 connecting the battery modules 10 and the charging module 20. Each battery module 10 is equipped with an independent combined contactor 50. The combined contactor 50 includes 3 DC contactors: 2 of which are branch contactors, respectively installed at both ends of the battery module 10, and 1 is a main circuit contactor, installed on the main circuit of the charging module 20, located on the line between the 2 branch contactors. By controlling the closing and opening of the DC contactors, the battery module 10 is disconnected. When a battery module 10 is fully charged, the main circuit contactor is interlocked with the two branch contactors, that is, the main circuit contactor is closed, the branch contactors are open, and the battery module 10 is disconnected.

[0027] In summary, the charging process of the centralized charging system for lithium batteries with different SOCs described in this utility model is as follows:

[0028] Step 1: Complete the system connection and power on as required;

[0029] Step 2: The BMS module 40 detects the individual battery information of each battery module 10 in real time, and transmits the individual battery information of all battery modules 10 to the centralized control module 30 through CAN communication. The centralized control module 30 controls the combination contactor 50 of the corresponding battery module 10 to complete the switching in or out of the battery module 10 according to the received battery information.

[0030] Step 3: Based on the individual battery status information of all battery modules 10, the centralized control module 30 controls the charging module 20 to output a constant current to charge all battery modules 10 with a specified current through CAN or RS485 communication.

[0031] Step 4: The centralized control module 30 continuously acquires the status of individual cells of all battery modules 10. When the voltage of any individual cell of any battery module 10 reaches the specified charging cutoff voltage (e.g., for lithium iron phosphate batteries, the charging cutoff voltage of any individual cell can be 3.65V), the charging module 20 is controlled to stop charging. After a delay of 15 seconds, the combination contactor 50 of the corresponding fully charged battery module 10 is controlled to complete the disconnection of the corresponding battery module 10.

[0032] Step 5: After a 30-second delay, control the charging module 20 again to charge the remaining battery module 10 at a constant current.

[0033] Step Six: Following the operations in Steps Four and Five, recharge the remaining battery modules 10 sequentially until the last battery module 10 is recharged. Then, cut off the output of the charging module 20 and disconnect all combination contactors 50 to complete the recharging.

[0034] Therefore, this utility model effectively overcomes the various shortcomings of the prior art and has high industrial application value. The above embodiments are merely illustrative of the principles and effects of this utility model and are not intended to limit this utility model. Any person skilled in the art can modify or change the above embodiments without departing from the spirit and scope of this utility model. Therefore, all equivalent modifications or changes made by those skilled in the art without departing from the spirit and technical concept disclosed in this utility model should still be covered by the claims of this utility model.

Claims

1. A centralized charging system for lithium batteries with different SOCs, characterized in that, include Multiple battery modules; The charging module is connected to multiple battery modules sequentially via a power harness; Multiple combination contactors are disposed on the power harness, and each combination contactor controls the connection and disconnection between one of the battery modules and the charging module.

2. The centralized charging system for lithium batteries with different SOCs according to claim 1, characterized in that, The combined contactor includes three DC contactors; two of them are branch contactors, respectively located at both ends of the battery module, and one is a main circuit contactor, located on the main circuit of the charging module, between the two branch contactors.

3. The centralized charging system for lithium batteries with different SOCs according to claim 2, characterized in that, The charging module is a 1500V high-voltage charging module.

4. The centralized charging system for lithium batteries with different SOCs according to claim 1, characterized in that, It also includes a BMS module, which is connected to the battery module via a communication harness, for monitoring and collecting the status of individual cells in the battery module.

5. The centralized charging system for lithium batteries with different SOCs according to claim 4, characterized in that, It also includes a centralized control module, which is connected to the charging module and the BMS module via communication harnesses.

6. The centralized charging system for lithium batteries with different SOCs according to claim 5, characterized in that, The BMS module includes a BMS slave controller and a BMS master controller; each battery module is equipped with one BMS slave controller; the BMS master controller is connected to the centralized control module and multiple BMS slave controllers via a communication harness.

7. The centralized charging system for lithium batteries with different SOCs according to claim 6, characterized in that, The BMS slave controller can simultaneously support up to 8 of the battery modules online, with a total voltage ≤1500V.

8. The centralized charging system for lithium batteries with different SOCs according to claim 5, characterized in that, The centralized control module controls the output of the charging module via CAN or RS485 communication based on the individual battery status of all the battery modules, so as to charge all the battery modules with a constant current at a specified current.

9. The centralized charging system for lithium batteries with different SOCs according to claim 8, characterized in that, When the voltage of a single cell in any of the battery modules reaches the specified charging cutoff voltage, the centralized control module controls the charging module to stop charging. After a delay of 10s to 20s, the module controls the combined contactor of the corresponding fully charged battery module to disconnect the fully charged battery module.

10. The centralized charging system for lithium batteries with different SOCs according to claim 9, characterized in that, After a fully charged battery module is switched off, after a 30-second delay, the centralized control module controls the charging module to perform constant current charging on the remaining battery modules.

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