Charging and discharging active equalization circuit for lithium ion power battery pack

Abstract

The invention provides a charging and discharging active equalization circuit for a lithium ion power battery pack. A voltage acquisition module and a voltage equalization circuit are arranged for each battery package of the power battery pack. The voltage of each battery individual is acquired in real time through the corresponding voltage acquisition module and sent to a battery management system. When the voltage of each battery individual or each battery package or the power battery pack exceeds a set upper limit and a set lower limit, voltage equalization is conducted; each voltage equalization circuit comprises a transformer and equalization switch MOS transistors. Each battery individual in power packages, each battery package in the power battery pack and the whole power battery pack are respectively connected to a winding of the same-core transformer through the corresponding two equalization switch MOS transistors. The equalization switch MOS transistors are controlled to be switched on or off, so that the corresponding equalization voltage is coupled on the corresponding transformer, and charging and discharging operation is achieved. According to the charging and discharging active equalization circuit, the active equalization process is flexible, rapid and efficient, the battery charging and discharging state can be effectively managed, use efficiency of the battery pack is improved, the service life of batteries is prolonged, equalization modes are flexible, and adaptability is high.

Description

technical field [0001] The invention belongs to the technical field of battery charge and discharge, and in particular relates to an active equalization circuit for charge and discharge of a lithium-ion power battery pack. Background technique [0002] Modern electric vehicles mostly use series power battery packs, and lithium-ion power batteries will be used in large quantities in the future. The safe and efficient use of power batteries is of great significance to the normal operation of electric vehicles. [0003] Due to the craftsmanship and other reasons in the production process of the cells in the battery pack, it is difficult to ensure that all the cells have a good consistency, so there are differences between the cells, even if the same batch, the same type of battery , There are also differences in capacity and internal resistance. After continuous charge and discharge cycles, the inconsistency of this monomer will be exacerbated, which will accelerate the capac...

AI Technical Summary

Problems solved by technology

[0004] Aiming at the unbalanced charging and discharging problem of the power battery pack existing in the prior art, the present invention provides a

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