Open AccessEnhanced EKF and SVSF for state of charge estimation of Li‐ion battery in electric vehicle using a fuzzy parameters model
Author(s) -
Ben Lazreg Meriem,
Jemmali Sabeur,
Manai Bilal,
Hamouda Mahmoud
Publication year - 2022
Publication title -
iet electrical systems in transportation
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.588
H-Index - 26
eISSN - 2042-9746
pISSN - 2042-9738
DOI - 10.1049/els2.12056
Subject(s) - control theory (sociology) , state of charge , extended kalman filter , battery (electricity) , fuzzy logic , mean squared error , standard deviation , kalman filter , equivalent circuit , algorithm , voltage , engineering , mathematics , computer science , power (physics) , electrical engineering , physics , statistics , control (management) , artificial intelligence , quantum mechanics
The precision of equivalent circuit model (ECM)‐based state of charge (SoC) estimation methods is vulnerable to the variation of the battery parameters, due to several internal and external factors. In this regard, this study proposes a fuzzy logic method for the approximate estimation of the ECM parameters at different temperatures and SoC levels. The fuzzy inference system is designed to handle the non‐linear deviation of the battery parameters from their reference values. On this basis, the extended Kalman filter and smooth variable structure filter are used to estimate the SoC. The two algorithms with fuzzy parameters (FP), namely FP‐EKF and FP‐SVSF, are tested on a 20 Ah Nickel Manganese Cobalt cell with maximum voltage of 4.2 V. The results show that the maximum root mean square error (RMSE) of the estimated SoC is kept within 1.51% with the FP‐EKF and 0.68% with the FP‐SVSF. Moreover, the reduction of the maximum absolute error may reach 0.34% with the FP‐EKF, and 0.82% with the FP‐SVSF, compared to the same algorithms without the proposed FP method. The executable codes are implemented on a low‐cost controller, and the average computational time is obtained as 215 μs, which confirms the real‐time practicality of the proposed method.