Estimation of Liquid Metal Battery Parameters of Thevenin Circuit Model Using Levenberg-Marquardt Algorithm

Inhalt:
This paper proposed a model designed specifically for Liquid Metal Battery (LMB), which is a potential energy storage battery with advantages of high energy density and long service life. The electrical properties of LMB are quite different from those of lithium batteries or lead-acid batteries. In the process of charging and discharging, the existing model cannot effectively describe the transient behavior of the battery. Firstly, a synthetic equivalent model consists of Thevenin’s circuit model and mathematical model was established, according to the unique battery transient behavior caused by the characteristics of LMB. Based on the dataset acquired by experiment, the parameters of the equivalent model were obtained by Levenberg-Marquardt algorithm. Secondly, a simulation model was built according to the battery model in MATLAB/Simulink. At last, comparison of the terminal voltage between estimated and measured value was made to verify the validity and accuracy of the battery model. The root-mean-square error between the two sets of data is less than 0.0107 and 1.41 %, most of the time.