Full parameters adaptive estimation for state of charge in lithium-ion batteries
SONG Dan-dan
GAO Zhe
CHAI Hao-yu
JIAO Zhi-yuan
Abstract：Considering the significant impact of initial state of charge(SOC)uncertainty on estimation accuracy in SOC estimation for lithium-ion batteries,an adaptive fractional-order extended Kalman filter(AFEKF)approach with initial value compensation mechanism is proposed.According to the fractional-order characteristics of batteries,a fractional-order equivalent-circuit model with two constant phase elements is constructed,and the equation of the fractional-order equivalent-circuit model describing the entire charging and discharging process of battery is discretized.In order to improve the adaptability of SOC estimation under complex operating conditions,the linear Kalman filter is used to identify the coefficients in the measurement equation online.In addition,in order to solve uncertainties in parameters,fractional-order dynamics,initial values of the equivalent circuit models and noises in the discretized state equation,the Sage-Husa filter and AFEKF approach with initial compensation are introduced.Finally,the performance difference between AFEKF with initial value compensation and AFEKF without initial value compensation is analyzed by comparative experiments,and SOC estimation experiments of AFEKF with initial value compensation are carried out under different working conditions.The experimental results show that the proposed SOC estimation approach exhibits strong adaptability in complex operating conditions.
Keywords：fractional-order modelextended Kalman filterstate of chargeinitial value compensationadaptive esti-mation
Publication Date：2025-06-30
Online Publishing Date：2025-08-15(First online date of this platform, not the publication date of the document)
Pages：10( 1160-1169 )