Method and system for parallel use of lithium battery modules

A battery management system, lithium battery technology, applied in circuits, electrical components, secondary batteries, etc., can solve the problems of BMS circuit damage and high current, and achieve the effect of avoiding large current shock, reducing voltage difference, and improving safety.

Active Publication Date: 2011-06-01
HUAWEI TECH CO LTD
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

In this process, due to the small internal resistance of the battery pack, a large current will be generated due to the voltage difference between different battery packs, which will cause damage to the BMS circuit

Method used

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  • Method and system for parallel use of lithium battery modules
  • Method and system for parallel use of lithium battery modules
  • Method and system for parallel use of lithium battery modules

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0037] Embodiment 1: charging voltage equalization parallel mode

[0038] see image 3 , image 3 It is a schematic diagram of the charging voltage equalization parallel mode of this embodiment, including:

[0039] S31, sort the voltage values ​​of each lithium battery module not connected to the busbar from low to high;

[0040] S32, according to the sorting result, connect the lithium battery module with the lowest voltage value to the busbar for charging;

[0041] S33, when the voltage value of the busbar rises to the voltage value of the second-lowest lithium battery module, connect the second-lowest lithium battery module to the busbar for charging;

[0042] S34, and so on, until all lithium battery modules are connected to the busbar.

[0043] by figure 2 The shown system structure diagram is illustrated as an example. When the system is powered on initially, the BMS of all lithium battery modules disconnects the lithium battery modules from the busbar, and is in a...

Embodiment 2

[0044] Embodiment 2: Discharge voltage equalization parallel mode

[0045] see Figure 4 , Figure 4 It is a schematic diagram of the parallel discharge voltage equalization mode of this embodiment, including:

[0046] S41, sort the voltage values ​​of each lithium battery module not connected to the busbar from high to low;

[0047] S42, according to the sorting result, connect the lithium battery module with the highest voltage value to the busbar for discharging;

[0048] S43, when the voltage value of the busbar drops to the voltage value of the second highest lithium battery module, connect the second highest lithium battery module to the busbar to discharge;

[0049] S44, and so on, until all lithium battery modules are connected to the busbar.

[0050] The hardware structure of the parallel discharge voltage equalization mode is the same as that of the charging voltage equalization parallel mode, but there are some minor differences in the software programming. sti...

Embodiment 3

[0051] Embodiment 3: Charge and discharge voltage equalization parallel mode

[0052] see Figure 5 , Figure 5 It is a schematic diagram of the parallel charging and discharging mode of voltage equalization in this embodiment, including:

[0053] S51, calculate the average voltage value of the voltage values ​​of the lithium battery modules not connected to the busbar;

[0054] S52, connecting the lithium battery modules whose voltage value is lower than the average voltage value to the busbar in order from low to high for charging, until the voltage value of the busbar rises to the average voltage value;

[0055] S53, connect the lithium battery modules whose voltage value is higher than the average voltage value to the busbar in order from high to low for discharging, until the voltage value of the busbar drops to the average voltage value.

[0056] Specifically, the lithium battery module whose voltage value is lower than the average voltage value is connected to the bu...

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PUM

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Abstract

The embodiment of the invention provides a method and system for parallel use of lithium battery modules. The method comprises the following steps: collecting a voltage value of each lithium battery module at the time of initial power-on; and controlling a voltage D-value between each lithium battery module and a busbar based on a voltage-sharing mode in accordance with the collected information,connecting the lithium battery modules to the busbar in sequence, wherein the lithium battery modules have minimum voltage D-values between the lithium battery modules and the busbar, and simultaneously charging and discharging the lithium battery modules which are connected to the busbar. According to the invention, the lithium battery modules can be connected in parallel after the voltage D-values of the lithium battery modules are kept within a range, thus reducing voltage difference among the lithium battery modules and avoiding large current impact among the lithium battery modules, thereby reducing damages to a battery management system (BMS) circuit and improving the safety of the parallel use of the lithium battery modules.

Description

technical field [0001] The invention relates to a parallel use method and system of lithium battery modules. Background technique [0002] Lithium batteries have high energy density, high single cell voltage, long life, no memory effect, and no pollution. Therefore, the use of lithium batteries for power supply is the development trend of battery applications. In high-power applications, firstly, single cells are required to be connected in series to form a battery pack to increase the supply voltage, and then the battery packs are connected in parallel to increase the output power of the power supply. A battery management system (Battery Management System, BMS) is required to monitor and manage both the single cell and the battery pack connected in series. The lithium battery pack and BMS together form a lithium battery module. [0003] The main problem existing in the parallel use of lithium battery modules is the large current impact between groups. Due to the differen...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): H01M10/42H01M10/44
CPCH01M10/4207H01M10/441Y02E60/12Y02E60/10
Inventor 水伟刘新宇刘伟
Owner HUAWEI TECH CO LTD
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