Battery capacity and SOC estimation method based on charging curve difference of single batteries in battery pack

• Main Authors: OUYANG MINGGAO, PANG KANG, ZHENG YUEJIU
• Format: Patent
• Language: Chinese; English
• Published: 18.05.2021
• Subjects: MEASURING; MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES; PHYSICS; TESTING

The invention relates to a battery capacity and SOC estimation method based on charging curve differences of single bodies in a battery pack. The battery capacity and SOC estimation method comprises the following steps: 1) establishing a theoretical corresponding relation between the capacity and SOC and the slope and intercept of charging time interval difference curves of the single bodies; 2) based on the charging data, finding a first cell reaching a charging cut-off voltage of the battery pack as a reference cell, and selecting other cells (except the reference cell) as to-be-tested cells; 3) calculating the internal resistance difference between the reference monomer and the to-be-measured monomer, and translating the reference monomer charging curve up and down to obtain a reference monomer charging curve after the internal resistance difference is corrected; 4) obtaining a charging time interval difference curve of the reference monomer and the to-be-measured monomer by using an interpolation method,