Active equalizer circuit of lithium cell pack

Abstract

The invention relates to an active equalizer circuit of a lithium cell pack. The active equalizer circuit comprises a DC / DC (Direct-Current / Direct-Current) converter and a switch array, wherein the switch array is composed of four groups of switches which are correspondingly connected with monomer cells in the lithium cell pack; one ends of the first group of switches are connected with the positive electrodes of the monomer cells respectively, and the other ends of the first group of switches are in short circuit and are connected with the input positive end of the DC / DC converter; one ends of the second group of switches are connected with the negative electrodes of the monomer cells respectively, and the other ends of the second group of switches are in short circuit and are connected with the input negative end of the DC / DC converter; one ends of the third group of switches are connected with the positive electrode of the monomer cells respectively, and the other ends of the third group of switches are in short circuit and are connected with the output positive end of the DC / DC converter; and one ends of the fourth group of switches are connected with the negative electrodes of the monomer cells respectively, and the other ends of the fourth group of switches are in short circuit and are connected with the output negative end of the DC / DC converter. The active equalizer circuit has the main function that the direct bidirectional energy conversion between any two monomer cells is realized, thereby achieving the purpose of equalizing the electric quantity of all monomers ultimately.

Description

technical field [0001] The invention relates to an active equalization circuit for a lithium battery pack, in particular to an active equalization circuit for a multi-cell serial power lithium battery pack. Background technique [0002] Lithium-ion batteries, especially lithium-ion power batteries, are becoming more and more widely used and have become an important direction for the development of new energy technologies. The larger the capacity of the single battery, the greater the difference in capacity of the single battery. There are two types of inconsistencies in the use of large-capacity lithium-ion batteries in groups. The first type of inconsistency is caused by differences in actual capacity, and the second type of inconsistency is caused by differences in initial power. Due to the inconsistency, one cell will be full first during charging, and another cell will be empty first during discharging. These defects limit the charge and discharge capacity of the entire...

AI Technical Summary

Problems solved by technology

[0004] The purpose of the present invention is to provide a battery pack active equalization circuit with a simple circuit to solve the problems of complex structure and high control requirements of the existing active equalization circuit

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