Modeling of Dynamic Hysteresis Characters for the Lithium-Ion Battery

The strategies of battery management system (BMS) rely heavily on sets of models to represent the lithium-ion batteries. However, the hysteresis voltage response of the batteries, which is mainly caused by the polarization of the electrodes, will inevitably have influence on the accuracy and real-time performance of the model's SOC-OCV curve, more or less. In this work, a dynamic Prandtl-Ishlinskii model is established to present a certain magnitude of hysteresis regarding not only the major OCV boundaries but also the different minor loops of partial charge and discharge. The relationship between SOC and hysteresis behavior of the battery's voltage is investigated through a self-designed pulsed-current test over a range of operating temperatures. Finally, the dynamic performance of the model is verified by the results obtained from the electric vehicle under dynamic driving cycle. The proposed model can significantly improve the accuracy of the model based SOC estimator as well as the robustness in terms of initial voltage error and current error.