Voltage equalization circuit and method for single batteries in battery module

Abstract

The invention discloses a voltage equalization circuit and method for single batteries in a battery module. The battery module comprises n single batteries which are sequentially connected in series, and the n single batteries are sequentially divided into n / 4 single battery groups; four cells in each single battery group are equally divided into two battery units, each battery unit is composed of two adjacent cells, and the two adjacent battery units share one CUK converter equalization circuit. Two cells in each battery unit share one inductor as an active equalization inductor; each battery single group consists of every two battery units, and each battery single group and the whole battery module are provided with one transformer for equalization. The number of the primary windings of the transformer is 1 / 4 of the original number, the number of the equalization resistors is only half of the number of the equalization resistors in an existing scheme, transformer equalization and CUK converter equalization are active equalization achieved in an energy transfer mode, almost no energy loss exists in the equalization process, and the battery equalization efficiency and the energy utilization rate are greatly improved.

Description

technical field [0001] The invention relates to the field of batteries, in particular to a voltage equalization circuit and method for battery cells in a battery module. Background technique [0002] There must be inconsistencies in the voltage, capacity, internal resistance, etc. of the single cells in the battery pack during the manufacturing and use process, and it is a process of continuous accumulation. The longer the time, the greater the difference between the single cells; and the lithium-ion battery The single group will also be affected by the use environment, and the inconsistency of the single battery will be gradually amplified during use, which will lead to accelerated degradation of the performance of some single batteries. [0003] At present, the solution to the inconsistency of the battery is to do battery balancing, that is, during the cycle of use, the energy of the individual cells in the battery group is balanced in a timely manner by means of energy co...

AI Technical Summary

Problems solved by technology

The main advantage of this method is that the circuit structure is simple and the cost is low; the main disadvantage is that the equalization process consumes excess power to achieve a balanced state, a lot of power will be lost in the circuit, and the utilization rate of energy is very low.

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