Distributed battery management system and method for lead-acid storage battery pack equalization

Abstract

Provided is a distributed battery management system and method for lead-acid storage battery pack equalization. Multiple lead-acid storage batteries are connected in series to form a series lead-acid storage battery unit. Multiple series lead-acid storage battery units are connected in parallel to form a lead-acid storage battery pack. The output end of the lead-acid storage battery pack is connected with a master control unit. Each lead-acid storage battery is connected with a slave control unit. A constant-current / voltage equalization device in the master control unit is connected with the corresponding lead-acid storage battery pack through the equalization switch of the slave control unit. Each slave control unit acquires the output voltage signal of the corresponding lead-acid storage battery and sends the output voltage signal to the master control unit. The master control unit acquires a maximum voltage signal and a minimum voltage signal of the multiple lead-acid storage batteries. When a voltage difference between the maximum voltage signal and the minimum voltage signal is greater than a preset threshold, the master control unit controls the constant-current / voltage equalization device and the equalization switch to perform equalization operation on the lead-acid storage battery corresponding to the minimum voltage signal. The distributed battery management system and method achieve organic combination of cost and circuit reliability.

Description

technical field [0001] The invention belongs to the technical field of new energy, and in particular relates to a distributed battery management system and method for equalizing lead-acid battery packs. Background technique [0002] In the new energy market, lead-acid batteries (including lead-carbon batteries) have always occupied an important position. The electrochemical reaction principle of lead-acid batteries is to convert electrical energy into chemical energy for storage in the battery during charging, and convert chemical energy into electrical energy for external systems during discharge. [0003] Due to the electrochemical characteristics of the lead-acid battery itself, it is not sensitive to the overcharge and overdischarge behavior of the current, and generally does not appear to burn and explode, which is different from lithium batteries. Therefore, it is generally believed that lithium battery packs require external management or protection circuits, while l...

AI Technical Summary

Problems solved by technology

[0004] (1) However, the quality consistency of mass-produced lead-acid battery cells is often difficult to ensure. For example, the difference in internal sulfuric acid concentration directly affects the battery cycle life, which makes each battery cell have differences in performance; especially when the battery is used After a period of time, the differences between battery cells become more obvious

[0005] (2) In the process of extensive use, when a lead-acid battery cell is over-discharged, the life of the lead-acid battery cell will also be seriously affected, and the difference between the battery cells is more obvious;

[0006] (3) In the process of extensive use, when a certain lead-acid battery cell encounters an excessive current, it may accelerate the loosening of lead dioxide on the positive electrode of the battery, and the life of this lead-acid battery cell will also be seriously affected. The difference between the more obvious;

[0007] (4) During extensive use, when a lead-acid battery cell is overcharged, the internal temperature rises and a large amount of gas is precipitated, which may cause the active material of the positive plate to fall off due to gas impact, and the positive grid alloy may Corroded by anodic oxidation, the life of the lead-acid battery will be seriously affected, and the difference between the battery cells will be more obvious;

[0009] (6) During the storage period of the lead-acid battery, the self-discharge phenomenon of the battery also makes a difference between the battery cells;

[0010] (4) Although lead-acid batteries should be prevented from mixing new and old batteries in the use of lead-acid batteries, the phenomenon of mixing old and new batteries still exists in many occasions, resulting in obvious differences in the monomers in the battery pack;

However, it is very expensive to use this battery management system for lithium batteries for lead-acid batteries, and it is not suitable for low-cost lead-acid batteries.

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