Equalization control method, device and system of battery

Abstract

The invention discloses an equalization control method, device and system of a battery. The control method comprises the steps of acquiring output voltages and output currents of each battery and eachbattery module, and estimating electric quantity of the battery and the battery module; processing difference between the output voltage of each battery module and a reference voltage by an error regulator to obtain a public reference current; adjusting the public reference current by feeding forward electric quantity of the battery to obtain a current reference value of each battery; and performing feedback regulation on the public reference current, and controlling a charging current of a corresponding battery. The reference current of each battery is changed according to the electric quantity of each battery, the reference current is adjusted by feedback, so that the size of the charging current is controlled, and the electric quantity of each battery is equalized.

Description

Technical field [0001] The present invention relates to the field of distributed power generation technology, in particular to a battery balance control method, device and system. Background technique [0002] In recent years, lithium-ion battery packs have been widely used in electric vehicles, medical equipment, new energy storage systems and other fields. The nominal voltage of a single lithium ion battery is 3.7V, so it is necessary to connect some battery cells in series to form a battery pack to obtain high voltage output. However, due to differences in the manufacture of lithium ion battery cells, aging attenuation, temperature gradient and other inconsistencies, the increase The battery pack is damaged, catches fire or even explodes, and seriously affects the service life of the battery pack. [0003] At present, series-type active equalization circuits are commonly used to correct inconsistencies in lithium-ion battery packs. However, series-type active equalization circu...

AI Technical Summary

Problems solved by technology

The nominal voltage of a single lithium-ion battery is 3.7V, so it is necessary to connect some battery cells in series to form a battery pack to obtain a high voltage output. It reduces the possibility of battery pack damage, fire or even explosion, seriously affecting the service life of the battery pack

[0003] At present, series active equalization circuits are widely used to correct inconsistencies in lithium-ion battery packs. However, series active equalization circuits usually have the following problems. First, the equalization speed is slow. For example, the equalization circuit consists of 20 battery cells. Assuming that the efficiency of each equalizer is 95%, in order to equalize the first and last battery, all equalizers need to work to transfer the energy of the first and last battery, so the final efficiency is only 35% %; Second, the reliability is poor. When a battery cell in the series battery fails, the equalization circuit will be interrupted; third, the scalability is poor, and the series equalization circuit is biased towards customized design. Users should not change the system configuration during use. Follow the actual demand, flexibly change the output power

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