Power battery pack active equalization system based on auxiliary power supply and use method

Abstract

A power battery pack active equalization system based on an auxiliary power supply comprises the auxiliary power supply, an electric control unit and battery packs, each battery pack comprises a plurality of single batteries which are sequentially connected in series, the adjacent battery packs are mutually connected in series, and all the battery packs are sequentially connected in series to form a power battery pack; the electric control unit comprises an MOS field effect transistor, an excitation inductor, a diode, a capacitor and a transformer. The transformer comprises a primary side coil and a secondary side coil which are arranged oppositely. During application, a layered and modularized active equalization charging strategy is adopted, and the first layer is charging equalization by taking a group as a unit through an electric control unit so as to realize SOC equalization of each battery pack; and the second layer is used for controlling the charging and standing of each battery monomer by controlling the on-off of the bypass switch of each battery monomer in the same group so as to realize the SOC balance of each battery monomer in the same group. According to the design, the battery protection effect is good, control is easy, and the control cost is low.

Description

technical field [0001] The invention relates to a new energy battery technology, which belongs to the field of new energy vehicles, and in particular to an active equalization system and usage method of a power battery pack based on an auxiliary power supply. Background technique [0002] With the rapid development of new energy vehicles in the world, lithium-ion batteries with high energy density, long cycle life, low natural discharge rate and no memory effect are more and more widely used. Due to the low voltage and small capacity of lithium battery cells, in electric vehicles, lithium batteries work by connecting multiple cells in series and in parallel to form a power battery pack to meet the requirements of output voltage and capacity. However, lithium batteries are affected by factors such as production process and raw material differences in the production process. Even for batteries produced in the same batch, there will be inconsistencies in voltage, capacity, SOC ...

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Problems solved by technology

[0007] The purpose of the present invention is to overcome the defects and problems existing in the prior art that it is difficult to protect the battery and control the cost at the same time, and to provide a power battery pack based on an auxiliary power supply with better battery protection effect, easy control, and lower control cost Active equalization system and method of use

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