A control method, device and battery box for realizing balanced charging of battery packs

Abstract

The invention discloses a control method and a device for achieving equalizing charge of a battery pack and a battery box. The control method for achieving the equalizing charge of the battery pack comprises periodically checking battery status signals of the battery pack, wherein the battery status signals comprise a battery state of charge (SOC), internal resistance, a voltage, a current and / or temperature, judging whether batteries in the battery pack need conducting equalizing charge or not according to the battery status signals, and if the batteries need conducting the equalizing charge, then the equalizing charge is conducted to the batteries through an equalization unit connected with the batteries. According to the control method and the device for achieving the equalizing charge of the battery pack and the battery box, the battery status signals such as the battery SOC, the internal resistance, the voltage, the current, the temperature and the like can be combined, the actual state equilibrium of the batteries is achieved, a switch topological structure and control are high in efficient and stability, the size of a magnetic element is greatly reduced, and achieving by using an integrated circuit can be easily achieved.

Description

technical field [0001] The invention relates to the technical field of electric vehicles, in particular to a control method, a device and a battery box for realizing balanced charging of battery packs. Background technique [0002] An electric vehicle refers to a vehicle powered by a vehicle-mounted power supply, driven by a motor to drive the wheels, and conforming to the requirements of road traffic and safety regulations. At present, electric vehicles have a wide range of application scenarios. Electric vehicles generally use standard batteries as their power source. However, during the manufacturing process of the single battery, the performance is dispersed, and the internal environment of the battery pack is also non-uniform during use, so as the use time increases, the performance difference between the single batteries will gradually widen , and if no corresponding measures are taken to reduce this difference, it will cause the consequences of overcharging some sin...

AI Technical Summary

Problems solved by technology

However, during the manufacturing process of the single battery, the performance is dispersed, and the internal environment of the battery pack is also non-uniform during use, so as the use time increases, the performance difference between the single batteries will gradually widen , and if no corresponding measures are taken to reduce this difference, it will cause the consequences of overcharging some single cells, overdischarging some single cells, overcharging and overdischarging, which will not only affect the service life of the battery, but also damage battery, but also may generate a lot of heat causing the battery to burn or explode

[0003] In the prior art, when the batteries of electric vehicles are used in series, the capacity of each battery cell will decrease after the battery pack is used for a long time due to the battery quality, batch and other reasons and the damage of individual cells during use. There is a difference, and this difference will become larger and larger over time, resulting in that when charging multiple batteries in the battery pack at the same time (that is, under the same current condition), the battery cell with a large capacity is always at In the state of shallow charge and shallow discharge, the capacity of the battery cell decays slowly and has a longer service life; compared with the battery cell with large capacity, the battery cell with small capacity is always in the state of overcharge and over discharge, and the battery cell with small capacity The core capacity will accelerate the decay and shorten the life

Since the life of the battery pack is determined by the life of the worst cell, the overall life of the battery pack will decrease accordingly.

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