Balancing-Aware Charging Strategy For Series-Connected Lithium-Ion Cells: A Nonlinear Model Predictive Control Approach
For battery management system designers, this work offers a practical MPC approach to mitigate charge unbalance in series-connected cells, though it is incremental as it builds on existing model-based optimization methods.
The paper presents a nonlinear model predictive control (MPC) strategy for balancing-aware charging of series-connected lithium-ion cells, validated on commercial cells via simulation, showing improved charge balance and charging performance.
Charge unbalance is one of the key issues for series-connected Lithium-ion cells. Within this context, model-based optimization strategies have proven to be the most effective. In the present paper, an ad-hoc electrochemical model, tailored to control purposes, is firstly presented. Relying on this latter, a general nonlinear MPC for balancing-aware optimal charging is then proposed. In view of the possibility of a practical implementation, the concepts are subsequently specialized for an easily implementable power supply scheme. Finally, the nonlinear MPC approach is validated on commercial cells using a detailed battery simulator, with sound evidence of its effectiveness.