Active balancing circuit and method of serial storage battery pack

Abstract

The invention discloses an active balancing circuit and method of a serial storage battery pack. The circuit includes a serial storage battery pack, an electronic switch network, a bidirectional DC-DCmodule, a battery voltage collecting module, a control module and a selective DC-DC isolation power supply module. The serial storage battery pack is composed of a plurality of storage battery piecesconnected in series. The serial storage battery pack is connected with the electronic switch network. The other end of the electronic switch network is connected to the bidirectional DC-DC module. The other end of the DC-DC module is connected to the output terminal of the serial storage battery pack. The control module enables connection of a battery piece requiring balancing through controllingthe electronic switch network and controls the bidirectional DC-DC module to perform charge or discharge balancing on the battery piece enabled to be in connection. According to the invention, through introducing the electronic switch network, efficient charge or discharge balancing can be performed on any storage battery piece in the serial storage battery pack by use of the only one bidirectional DC-DC module. The circuit has advantages of small element number, low cost, large balancing current, simple control and high robustness.

Description

technical field [0001] The invention relates to the field of battery management systems (BMS), in particular to an energy-transfer-type active equalization technology for series-connected battery packs. Background technique [0002] There are two main ways to balance the battery pack in series at present: passive balance and active balance. Passive equalization is widely used because of its simple circuit, convenient control and low cost, but also because of its small equalization current (tens to hundreds of milliamperes) and equalization only during charging, and there are energy losses and thermal management Difficulty and other problems are only suitable for occasions with relatively low requirements. Active equalization does not consume energy at the expense of energy consumption. The equalization current is large (ampere level), charging and discharging can be balanced, and the capacity of each battery can be utilized to the maximum. It is an ideal equalization method...

AI Technical Summary

Problems solved by technology

[0003] The purpose of the present invention is to solve the problems of complex control, high cost, and low reliability of the existing active equalization circuit, and provide an active equalization circuit and method for series battery packs with low cost, simple control process and easy implementation

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