Degradation-Model-Agnostic Energy Throughput Control for EV Range Preservation and Battery Lifetime Extension via Cell-Level Inverters

Artikel i vetenskaplig tidskrift, 2026

A conventional electric vehicle (EV) powertrain relies on a centralized high-voltage DC–AC inverter, thereby limiting cell-level control and potentially reducing overall driving range and battery lifetime. This paper studies an H-bridge-based cell-level inverter topology that performs power conversion at the cell level, enabling independent control of individual cells and expanding the design space for battery management. Leveraging these additional degrees of freedom, we propose a degradation-model-agnostic energy-throughput control strategy that preserves usable energy and EV range while extending battery-pack lifetime. Because usable energy (and thus driving range) and lifetime are governed by the cells with the lowest state-of-charge (SOC) and state-of-health (SOH), respectively, the proposed controller preferentially routes energy throughput to healthier cells. Specifically, during charging, it permits cell SOCs to diverge to promote SOH equalization; during discharging, it balances remaining usable capacity to maximize usable energy under per-cell constraints. The proposed SOC–SOH-aware control strategy is evaluated on two aging models representing lithium manganese oxide (LMO) and lithium iron phosphate (LFP) chemistries, using a Tesla Model 3 charge–discharge profile under a broad set of aging-model, controller-design, end-of-life (EOL), and estimation assumptions. In the reference case, which includes zero-mean SOH-estimation noise with a standard deviation of 2 percentage points, simulations show lifetime improvements of 13.0% and 8.9% for LFP and LMO batteries, respectively. These results show that the proposed controller can extend battery-pack lifetime without reducing usable energy, while requiring neither a specific aging model nor prior knowledge of the next trip.