Active balancing method for battery packs based on battery state of health and state of charge

Abstract

The invention discloses a battery pack active equalization method based on battery health state and charge state, the method comprises the following steps: At first, obtaining SOH and SOC of each single cell in the battery pack, with the SOH*SOC of each cell being used as the equalization coefficient, designing the active equalization circuit of direct energy transfer, inputting The equalization coefficient to the equalization circuit control module in the active equalization circuit as an initial condition, and controlling the closing of the circuit path by an equalization circuit control module according to a pre-written program to form a corresponding energy transfer channel until the difference of the remaining power of each cell reaches a set threshold value. The method can effectively reduce the negative impact of battery pack inconsistency on the power and life of the power battery, and is conducive to improving the power performance and economy of pure electric vehicles.

Description

technical field [0001] The invention relates to the field of battery power estimation, in particular to an active balancing method for battery packs based on battery health status and charge status. Background technique [0002] Due to reasons such as manufacturing and use environment, the inconsistency of the capacity and voltage of the battery pack exists objectively, so that the single cells in the battery pack cannot be charged and discharged synchronously. If the inconsistency cannot be effectively balanced, it will affect the life and power of the power battery. output power, which in turn leads to insufficient power of pure electric vehicles and a decline in economic performance. [0003] The research on inconsistency equalization methods for battery packs is mainly divided into two categories, one is passive equalization that dissipates battery power with high remaining power through series resistance; the other is active equalization through energy transfer within t...

AI Technical Summary

Problems solved by technology

[0004] The purpose of the present invention is to improve the accuracy of the existing method for estimating the remaining battery power, and on the basis of this method for estimating the remaining battery power, it provides an active balancing method for battery packs based on the state of health and state of charge of the battery. The above method uses SOH*SOC as the equalization coefficient (Equal Coefficient) to estimate the remaining capacity of the battery after aging, and uses the equalization coefficient of each single battery as the equalization index, so that the equalization coefficient after equalization, that is, the difference in the remaining power of each battery, reaches the set value. threshold, which overcomes the problem of low accuracy in estimating the remaining battery power by SOC after the battery ages

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