Energy Storage Science and Technology ›› 2024, Vol. 13 ›› Issue (2): 712-720.doi: 10.19799/j.cnki.2095-4239.2023.0605

• Energy Storage Test: Methods and Evaluation • Previous Articles     Next Articles

Lithium-ion battery parameter identification based on adaptive multilayer RLS

Shuangming DUAN(), Shengli ZHANG   

  1. Key Laboratory of Modern Power System Simulation and Control & Renewable Energy Technology, Ministry of Education(Northeast Electric Power University), Jilin 132012, Jilin, China
  • Received:2023-09-05 Revised:2023-09-10 Online:2024-02-28 Published:2024-03-01
  • Contact: Shuangming DUAN E-mail:duansm@neepu.edu.cn

Abstract:

Accurate identification of battery parameters is the foundation for achieving high-precision state estimation in electric vehicle battery management systems. To address the issue of insufficient accuracy when identifying changing battery parameters using the forgetting factor recursive least square (FFRLS) method, this study proposes an adaptive multilayer recursive least squares (AMLRLS) online battery parameter identification method, which updates parameters hierarchically. The AMLRLS algorithm uses the voltage error of the identified parameters of the L-1 layer as the target value for the L-th layer. It recursively separates the parameter quantities from the voltage error and aggregates them from all layers to form the identification result for a single data point, creating a MLRLS structure. To address the problem of computing up to the maximum set layer in each identification step, a layer selector is designed. It takes the voltage error from the FFRLS identification result of the first layer as input and adaptively selects the number of layers based on the magnitude of the voltage error, reducing computational load. A battery model is constructed, and simulations are conducted to verify the parameter tracking capability of AMLRLS. Results demonstrate that AMLRLS reduces parameter errors by up to 69% compared to RLS and 46.5% compared to adaptive FFRLS. In experimental validation, AMLRLS considerably reduces the root mean square error and average absolute error of voltage by 43.9% and 32.1%, respectively, under dynamic stress test (DST) conditions compared to other algorithms. Results across different currents, temperatures, and the initial state of charge conditions validate the strong applicability of AMLRLS. Finally, the computation time of various algorithms is compared. AMLRLS reduces computation time by 37.4% under DST conditions and by 28.6% under federal urban driving schedule conditions compared to scenarios without a layer selector, thus alleviating the computational burden of the battery management system.

Key words: lithium-ion battery, parameter identification, least squares, equivalent circuit model

CLC Number: