Multi-Objective Sizing of an Electric Aircraft Power System Under n-1 Contingency Constraints: Weight–Volume–Losses Trade-Offs

A multi-objective sizing framework for the Electric Power System (EPS) of a reference short-range electrified aircraft is presented under n-1 contingency constraints. The workflow integrates database-driven component sizing and selection in MATLAB with steady-state load-flow and contingency evaluation in DIgSILENT PowerFactory, so that the effect of post-outage re-sizing can be quantified consistently. A radial DC architecture is considered together with multiple propulsion distributions and a discrete DC grid voltage sweep. The EPS is evaluated in three states: Before Contingency (BeCon), After Contingency (AfCon), and After Contingency with Loss Refinement (AfConLF). The novelty of this work lies in the integrated contingency-aware and loss-refined multi-objective sizing framework, which enables a quantitatively grounded comparison of aircraft EPS architectures at system level. Multi-objective selection is carried out for the main EPS components and for the overall EPS using total weight, total volume, and steady-state losses at the maximum take-off operating point. The results show that enforcing contingency compliance shifts the feasible trade space toward higher weight, volume, and losses, with the strongest penalty occurring in the DC–DC conversion stage and upstream DC distribution. The AfConLF step preserves the hardware ratings obtained in AfCon while refining the loss estimate by using post-contingency load factors, thereby improving the realism of the steady-state assessment without materially increasing weight or volume. In addition, the influence of DC-grid voltage and motor design on the resulting EPS trade space is quantified, providing practical guidance for selecting contingency-compliant architectures for future electric aircraft.