Battery pack double-layer topological structure equalization circuit and method

Abstract

The invention discloses a battery pack double-layer topological structure equalization circuit and method. A first-layer topological equalization circuit comprises a multi-winding transformer, a control switch, a single battery in a small battery pack, a control switch K1_1 and a secondary winding of the multi-winding transformer, wherein the control switch K1_1 is connected with the secondary winding of the multi-winding transformer; the small battery pack and the control switch K1 are connected with a primary winding of the multi-winding transformer; the second-layer topology equalization circuit comprises a transformer and two control switches; a primary winding of the transformer, the control switch S1 and the main battery pack are connected; and a secondary winding of the transformer,the control switch S1_1 and the small battery pack are connected. Multiple groups of small battery packs or multiple battery monomers can be equalized at the same time, the battery equalization speedis greatly improved, the battery equalization time is shortened, and the equalization efficiency is improved.

Description

technical field [0001] The invention belongs to the field of battery equalization, and relates to a battery pack double-layer topological structure equalization circuit and method. Background technique [0002] Lithium-ion batteries have multiple advantages such as low production cost, high energy density, long service life, safety and stability, and are currently the most widely used batteries in the industrial and living fields. The basic characteristics and working principle of lithium-ion batteries determine that the battery cell has the characteristics of low voltage and small capacity. Usually, the rated working voltage of a lithium-ion battery cell is 3.2V to 4.2V, and the capacity of a single cell is only a few ampere hours. When it reaches tens of amps, it cannot meet the demand of some large instruments and equipment for energy sources. Therefore, in the application of lithium-ion batteries, hundreds or thousands of batteries are usually connected in series and pa...

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Problems solved by technology

[0005] Therefore, active equalization is generally used, but active equalization has voltage mutations caused by inconsistent equalization speeds, and when the number of single batteries is large or the distance between the first and last batteries is long, the equalization time is longer and the efficiency is lower.

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