Balanced charge control system of lithium ion storage battery group

Abstract

The invention relates to a balanced charge control system of a lithium ion storage battery group, which comprises a lower computer and N sets of same control circuits; N is the number of lithium ion storage battery units that the storage battery group comprises; and each control circuit comprises an electronic switch formed by serially connecting two Darlington triodes, and a shunt resistor. A level-type command sent out by the lower computer controls the connection and the disconnection of the shunt resistor. When in normal connection, two groups of bypass circuits are connected simultaneously; and each shunt resistor only bears half of the original load current. If one circuit of electronic switch is in short circuit failure, the balanced control performance is not affected; and if one circuit of electronic switch is in open circuit failure, the group of bypass circuits are disconnected, the other group of bypass circuits can continue to work, and the balanced control performance is not affected. In addition, a bypass control switch is changed from an original relay into the electronic switch, so that inherent defects of low reliability of a mechanical contact in the relay, restricted switching times and the like are overcome, and the system reliability is improved.

Description

technical field [0001] The invention relates to a control system for controlling the charging of a storage battery. Background technique [0002] Compared with traditional nickel-cadmium batteries and nickel-hydrogen batteries, lithium-ion batteries have the advantages of high specific energy, high working voltage, wide application temperature range, low self-discharge rate, long cycle life, and good safety. At present, the aerospace application of lithium-ion batteries has gradually increased at home and abroad, and has begun to be put into use. [0003] Lithium-ion batteries have superior performance, and at the same time, their use requirements are relatively strict. In engineering applications, lithium-ion battery cells or battery modules composed of single cells connected in parallel must be connected in series to form a battery pack, and the performance imbalance of each battery cell or battery module must be considered during the charging process. And as time goes b...

AI Technical Summary

Problems solved by technology

And as time goes by, this imbalance becomes more and more serious, which seriously affects the life and reliability of the battery pack. Balanced charge control is the key technology for lithium-ion battery pack charging

[0004] Commonly used equalization charge control systems such as figure 1 As shown, the control method of using a relay to control the on-off shunt resistance is affected by inherent defects such as low reliability of mechanical contacts and limited number of switches. Once the relay fails to open, the equalization function will be completely lost; Contact adhesion), a cell will continue to discharge, resulting in over-discharge of the cell, seriously affecting the control reliability of the system

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