LI C Y, ZHANG Y, ZHAO Y,et al.Online parameter identification of lithium battery equivalent circuit model based on HPPC-FFRLS[J].Journal of Henan Polytechnic University(Natural Science) ,2024,43(5):127-132.

doi:10.16186/j.cnki.1673-9787.2022080023

Received:2022/08/13

Revised:2022/12/19

Published:2024/07/31

Online parameter identification of lithium battery equivalent circuit model based on HPPC-FFRLS

LI Changyou, ZHANG Ying, ZHAO Yong, GAO Guofu

School of Mechanical and Power Engineering，Henan Polytechnic University，Jiaozuo 454000，Henan，China

Abstract: Objectives In order to realize high-precision condition monitoring and analysis of lithium-ion power battery，  Methods the study on the online identification of the parameters of the second-order RC equivalent circuit model of lithium-ion power battery was carried out.The second-order RC equivalent circuit model of lithium-ion power battery was constructed.The open-circuit voltage method and the ampere-time integration algorithm were combined to evaluate the state of charge（SOC） of the battery.The offline parameter identification of the equivalent circuit model was carried out through the experimental data of HPPC test.The offline identification results were taken as the initial value of the system state，and the recursive least squares algorithm with forgetting factor（FFRLS） was combined to carry out the online identification of the parameters of the second-order RC equivalent circuit model of the lithium-ion power battery.Simulink was used to build a simulation system of battery state monitoring and charge/discharge control，the model based on the online identification parameters was simulated and tested，and the experimental platform was built by using the programmable power supply and electronic load. Results Comparing the system simulation output of online parameter identification，offline parameter identification and experimental data，the results showed that：The simulation error of the model based on HPPC-FFRLS was reduced by 50% compared with that of the HPPC experimental method，the online identification strategy overcomed the influences of ambient temperature，aging of the battery，and charge/discharge rate；The fluctuation of the system at the early stage of the simulation was reduced significantly，and the equivalent model system dynamic tracking had a better level，the robustness got better.  Conclusions The online parameter identification of lithium battery equivalent circuit model based on HPPC-FFRLS ensured the effectiveness of the model parameters，improved the model accuracy，and reduced the calculation.

Key words:lithium battery;second-order RC equivalent circuit model;HPPC testing;online parameter identification;FFRLS