Battery pack equalization system and control method considering lifetime of batteries

Abstract

The invention discloses a battery pack equalization system and control method considering the lifetime of batteries. The system comprises a sampling module, an equalization module, a battery lifetimeprediction module and a control module, the battery lifetime prediction module receives battery information acquired by the sampling module and predicts the lifetime of the batteries, and the controlmodule is used for receiving the battery information, acquired by the sampling module, of a battery pack and battery lifetime information obtained by the battery lifetime prediction module, calculating a voltage difference of adjacent single batteries, determining whether the voltage difference reaches a preset value, determining the adjacent single batteries required for equalization and the timerequired for equalization, and controlling the execution of the equalization module when the battery pack enters a charging and discharging state. The voltage difference of the adjacent single batteries is corrected by employing the battery lifetime information provided by the battery lifetime prediction module, the condition that the differences of the lifetime attenuation degrees of different single batteries cause inconsistent open-circuit voltages of the batteries is effectively considered, the energy waste caused by over-equalization can be avoided, the equalization efficiency is improved, the equalization time is reduced, and the lifetime of the batteries is effectively prolonged.

Description

technical field [0001] The invention belongs to the field of battery pack equalization, and in particular relates to a battery pack equalization system and a control method considering battery life. Background technique [0002] In order to meet the large-capacity and high-power requirements of new energy vehicles, hundreds of single cells are generally used in series and parallel. The inconsistency of the single battery will lead to the imbalance of voltage and power when the battery is charged and discharged. As the number of charge and discharge increases, this imbalance will become more and more obvious, and eventually the life and capacity of the battery will decline rapidly. The balance control of the battery pack can improve the overall life of the battery pack and the utilization rate of the overall capacity, so it is of great significance. [0003] Battery equalization circuits are divided into dissipative and non-dissipative circuits. Dissipative circuits are les...

AI Technical Summary

Problems solved by technology

At the same time, due to the fact that the actual open-circuit voltage of the battery drops and the actual open-circuit voltage of different single batteries is not the same due to the failure of battery life decay, it leads to over-balancing among single-cell batteries, increases energy waste during equalization, reduces equalization efficiency, and increases The time required for a large equilibrium

For example, the Chinese patent publication number is CN105703440A, and the publication date is 2016-6-22. It discloses a battery equalization circuit, which uses capacitors to store the energy of single batteries with high voltage, and charges single batteries with low voltage, but does not consider battery life. Attenuation causes the actual open circuit voltage of the battery to decrease, which may lead to waste of transferred energy

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