MPC-Based Power Management for Energy Efficiency and Li-Ion Battery Degradation Mitigation in Off-Grid Hybrid Photovoltaic Inverters

Efficient power management in Hybrid Energy Storage Systems (HESS) for off-grid PV inverters remains a challenge, particularly in terms of energy efficiency and battery degradation mitigation. In this context, this paper proposes a Model Predictive Control (MPC) based power management designed to mitigate Li-ion battery degradation while improving the overall system efficiency. To validate this proposal, extensive experimental results are presented. The proposed formulation aims to minimize battery stress by smoothing the current profile and reducing cycling effects. The performance of the MPC power management is verified through a comparative experimental analysis of four distinct strategies: rule-based, frequency-filtering, a benchmark MPC, and the proposed MPC. Evaluation is based on four key metrics: RMS current, total power losses, Equivalent Full Cycles (EFC), and State of Health variation (ΔSOH). Experimental results demonstrate that the proposed method outperforms the compared strategies across all evaluated criteria, significantly reducing battery stress in terms of cycling and current distribution. Furthermore, long-term simulations corroborate these findings, showing a substantial reduction in battery degradation compared to other established methods. These results confirm that the proposed method, provides a robust solution for mitigating battery degradation in hybrid inverter applications.