Active equalization device for battery pack

Abstract

The invention relates to the field of lithium battery charging, and discloses an active equalization device for a battery pack. The active equalization device comprises a voltage sensor, two controllable switches, an inductor and a controller, and is characterized in that the voltage sensor is used for detecting voltage at both ends of each of the two battery units; the two controllable switches are respectively connected with the two battery units in series; the inductor is connected between a node between the two battery units and a node between the two controllable switches; and the controller is used for receiving voltage at both ends of each battery unit, judging whether the voltage at both ends of one of the two battery units is greater than the voltage at both ends of the other battery unit or not, closing the first controllable switch corresponding to battery unit when the voltage at both ends of one of the two battery units is judged to be greater than the voltage at both ends of the other battery unit so as to charge the inductor by one battery unit, disconnecting the first controllable switch, and closing the second controllable switch after the charging for the inductor is over to as to enable the inductor to charge the other battery unit.

Description

technical field [0001] The invention relates to the field of lithium battery charging, in particular to an active balancing device for a battery pack. Background technique [0002] In the field of electric power, lithium batteries have gradually become the mainstream power source for electric vehicles, energy storage and communication backup power due to their advantages such as high energy density, small size, and environmental protection. [0003] In actual use, lithium batteries are in the form of battery packs. However, due to factors such as the environment and production machines, lithium batteries will inevitably have slight performance differences during production, which leads to the fact that each lithium battery in the lithium battery pack may have different voltage values ​​for each battery. After repeated use, the voltage difference of these batteries will gradually increase. If equalization is not performed in time, these increasing inconsistencies will lead t...

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Problems solved by technology

However, since the equalization process is to convert electric energy into heat energy, corresponding cooling equipment must be configured in the heat dissipation process, which greatly increases the cost in industrial production and converts electric energy into heat energy will cause unnecessary power waste; in addition, if heat dissipation If it is unreasonable, it will cause the temperature of the entire battery combination equalization module to be too high, resulting in accelerated decay of the battery and the consequence of burning out the equalization module

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