Technical Dialogue Session
Transportation Power Electronics III
lithium-ion battery, battery management system, battery charging, model predictive control
This paper presents a novel application of model predictive control (MPC) to the problem of managing lithium-ion cell performance using a highly accurate low-order electro-thermal equivalent circuit model and experimentally validated via laboratory experiments. The proposed method uses MPC to ensure compliance with cell-level operational limits and has the potential to extend lifetime by mitigating certain mechanisms of cell degradation. A five-state electro-thermal model is developed, characterized and validated. Implementation employs an extended Kalman filter for state-estimation and MPC for controlling charge/discharge current. The method is experimentally validated using a 26650 cylindrical lithium-iron phosphate (LFP) cell. The new method: (i) develops a fully coupled electro-thermal model of cell dynamics; (ii) incorporates a dynamic hysteresis model to improve accuracy; (iii) employs a nonlinear Kalman filter for accurate state estimation to inform the MPC algorithm; and (iv) utilizes a modified form of MPC which correctly models direct feed-through behavior to characterize ohmic resistance.