Charge and discharge active equalization circuit of lithium-ion power battery pack

Abstract

The invention provides a charge and discharge active equalization circuit of a lithium-ion power battery pack, and belongs to the technical field of battery charge and discharge. The charge and discharge active equalization circuit comprises a charge and discharge active equalization circuit body between battery cells and a charge and discharge active equalization circuit body among a battery module, the battery cells and an external power source. The two charge and discharge active equalization circuit bodies are based on a supercapacitor. A battery cell selection circuit is used for selecting the battery cells about to be subjected to voltage equalization. A reversing circuit and the supercapacitor are used for carrying out voltage equalization management on the selected battery cells. The charge and discharge active equalization circuit body among the battery module, the battery cells and the external power source is used for achieving charge and discharge active equalization management among the battery module and the battery cells, charge and discharge active equalization management among the external power source and the battery cells and charge and discharge active equalization management between the external power source and the battery module. The equalization circuit is simple and reliable in equalization process, easy to control and fast and efficient in active equalization process, the charge state and the discharge state of a battery can be effectively managed, and then the service life of the battery is prolonged.

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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