Cell equalization system based on bidirectional DC/DC

Abstract

The invention relates to the cell equalization system technology field and especially relates to a cell equalization system based on bidirectional DC / DC. The cell equalization system comprises a cell module, a cell management unit and a power supply bus. The cell management unit comprises a single chip microcomputer, a bidirectional DC / DC module, a bidirectional polarity switch and a driving / interlocking circuit. An input terminal of the bidirectional DC / DC module is connected with the power supply bus. An output terminal of the bidirectional DC / DC module is connected with the input terminal of the bidirectional polarity switch. A charging / discharging equalization control terminal of the single chip microcomputer is connected with a control terminal of the bidirectional DC / DC module. A polarity switch control terminal of the single chip microcomputer is connected with the control terminal of the bidirectional polarity switch. The single chip microcomputer controls a bidirectional switch array through the driving / interlocking circuit. According to the invention, through using the single chip microcomputer to control the bidirectional DC / DC module, the bidirectional polarity switch and the bidirectional switch array, time sharing charging and discharging equalization of each cell in the cell module can be realized.

Description

technical field [0001] The invention relates to the technical field of battery balancing systems, in particular to a battery balancing system based on bidirectional DC / DC (direct current to direct current). Background technique [0002] In the high-voltage battery pack of new energy vehicles and energy storage systems, in order to ensure that the battery system has sufficient energy and prolong the service life of the battery pack, it is necessary to effectively balance the single cells connected in series in the high-voltage battery pack. Among the existing equalization technologies based on the inside of the battery module, some achieve passive discharge equalization by constructing an independent power resistor discharge circuit for each single battery. This is an energy-consuming discharge equalization method. At the same time, it will also cause heating problems; some of them pass the excess energy of the single battery to other single batteries through adjacent single ...

AI Technical Summary

Problems solved by technology

Among the existing equalization technologies based on the inside of the battery module, some achieve passive discharge equalization by constructing an independent power resistor discharge circuit for each single battery. This is an energy-consuming discharge equalization method. At the same time, it will also cause heating problems; some of them pass the excess energy of the single battery to other single batteries through adjacent single batteries in turn. The circuit composition and control structure of this balancing scheme are relatively complicated and require A large number of transformers or inductors and capacitors are also difficult to control EMC (electromagnetic interference) problems. At the same time, because it adopts a step-by-step energy transfer method to achieve equalization, the overall equalization efficiency is very low

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