A charging and discharging active equalization circuit for lithium-ion power battery pack

Abstract

The invention provides an active equalization circuit for charge and discharge of a lithium-ion power battery pack, which belongs to the technical field of battery charge and discharge. The invention includes two parts: an active charging and discharging equalization circuit between single batteries based on a supercapacitor and an active charging and discharging equalization circuit between a battery module, a single battery and an external power supply. The single battery selection circuit is used to select the single battery to be voltage balanced, and the commutation circuit and the supercapacitor are used to manage the voltage balance of the selected single battery. The charge and discharge active balance circuit between the battery module, the single battery and the external power supply realizes the active balance management of the charge and discharge between the battery module and the single battery, the active balance management of the charge and discharge between the external power supply and the single battery, and the charge and discharge between the external power supply and the battery module Active balance management. The equalization process of the equalization circuit of the present invention is simple and reliable, easy to control, the active equalization process is fast and efficient, and can effectively manage the charge and discharge state of the battery, thereby prolonging the battery life.

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] During the use of the battery pack, due to the inconsistency between the individual batteries, the difference caused by continuous charge and discharge cycles will accelerate the capacity decay of some individual batteries. Due to the craftsmanship and other reasons in the production process, even batteries of the same batch and type have differences in capacity, internal resistance, etc., and in the long-term use process, this difference will become larger and...

AI Technical Summary

Problems solved by technology

[0003] During the use of the battery pack, due to the inconsistency between the individual batteries, the difference caused by continuous charge and discharge cycles will accelerate the capacity decay of some individual batteries.

Due to the craftsmanship and other reasons in the production process, even batteries of the same batch and type have differences in capacity, internal resistance, etc., and in the long-term use process, this difference will become larger and larger, and then Unbalanced charging and discharging of the power battery pack

Imbalance has a great impact on the performance of the battery pack in series, which will reduce the overall capacity of the battery pack and shorten the service life

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