Charge-discharge equalizing circuit of multi-monomer tandem dynamic lithium battery

Abstract

The invention relates to a charge-discharge equalizing circuit of a multi-monomer tandem dynamic lithium battery, comprising a master control module and a group of equalizing modules, wherein the group of equalizing modules are communicated with the master control module and correspondingly connected with a group of monomer batteries which are sequentially connected in series; each equalizing module comprises a flyback transformer, two switches and one or more than two parallel capacitor banks; one winding of the flyback transformer of each equalizing module is connected with the positive and negative poles of the corresponding monomer battery; the capacitor banks of each equalizing module are connected with the winding in parallel; the other winding is connected with the positive and negative poles of the monomer battery which is adjacent to and sequentially connected to the above monomer battery; and each winding return circuit is connected with one switch in series. The equalizing circuit realizes energy balance among all the monomer batteries, has the advantages that the equalization is lossless, the equalizing current is large, the equalizing efficiency is high, the expandability is good and the implementation is easy, and the purposes of quick large-current charging, enhancement of battery safety performance, improvement of discharging capacity and service life of the batteries and the like can be realized.

Description

technical field [0001] The invention relates to a charge-discharge equalization circuit for a lithium battery pack, in particular to a charge-discharge equalization circuit for a power lithium battery pack with multiple cells connected in series. Background technique [0002] With the advancement of lithium-ion power battery technology, the consistency of the battery has been greatly improved. Nevertheless, the differences between the individual cells still exist, some batteries have a larger capacity and some have a smaller capacity. The voltage of a battery with a small capacity changes relatively quickly. When charging, it reaches the charging cut-off voltage first, and when discharging, it reaches the discharge cut-off voltage first. Similar to the short board effect of a wooden barrel, a battery with a small capacity limits the performance of the entire battery pack. With the increase of the number of cycles, the overshoot and overdischarge of individual batteries and...

AI Technical Summary

Problems solved by technology

[0004] The purpose of the present invention is to provide a charge-discharge equalization circuit for multi-unit series power lithium battery packs to solve the problem that the existing equalization circuit cannot achieve high-efficiency and high-current charge-discharge balance between any two units

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