Fuzzy probability comprehensive judgment-based battery state-of-health estimation method

Abstract

A fuzzy probability comprehensive judgment-based battery state-of-health estimation method belongs to the technical field of lithium iron phosphate battery estimation and aims to solve the problems that the state-of-health of a single battery cannot be ensured by a traditional health estimation technology to cause that the lifetime of a battery pack is remarkably reduced. The fuzzy probability comprehensive judgment-based battery state-of-health estimation method comprises the steps of obtaining estimation data by charge-discharge experiment on a battery to be estimated; obtaining a relation between a state-of-charge (SOC) value and a voltage during the charge-discharge process of the battery; performing normalization on voltage values of the battery under different SOCs, and then taking the voltage values as a state-of-health judgment object of each single battery; calculating an index weight forming an evaluation index coefficient, and determining the state-of-health of each single battery according to a maximum probability principle; and determining the state-of-health of the lithium iron phosphate battery pack by fuzzy comprehensive judgment according to a maximum membership principle. By health estimation on the grouped battery pack, the initialization performance of the battery pack can be greatly improved.

Description

technical field [0001] The battery health assessment method described in this application belongs to the field of lithium iron phosphate battery assessment. In particular, it relates to a battery health state evaluation method based on fuzzy probability comprehensive evaluation. Background technique [0002] Lithium iron phosphate batteries have the characteristics of good safety, environmental protection and long cycle life. Under standard charging and discharging conditions, the cycle life of lithium iron phosphate batteries is as high as 2,000 times, which is more than three times the life of other commonly used lithium-ion batteries. From the perspective of environmental protection, the lithium iron phosphate battery does not contain any precious metals or other metals that are harmful to the environment. In addition, the lithium iron phosphate battery has no memory effect and can be recharged whenever it is used without discharging and recharging. However, from a pro...

AI Technical Summary

Problems solved by technology

[0003] However, most of the current traditional health assessment technologies only test static parameters such as the capacity, voltage, and internal resistance of the single battery. Although this method is time-consuming and efficient, it can quickly complete the health assessment, but these static Parameters will change with the increase of battery usage time. At the same time, the analysis of the factors affecting the battery health status is not comprehensive. attenuation

Images