Architectural Design Considerations for Electric Power Systems in Future (More) Electric Aircraft

The aviation sector’s push for lower emissions and higher efficiency is accelerating the transition toward More Electric Aircraft (MEA) and ultimately All Electric Aircraft (AEA). This shift requires a fundamental redesign of the Electric Power System (EPS) to handle increased electrical loads while meeting strict requirements for weight, reliability, efficiency, safety, and power quality. This paper analyzes key architectural decisions for MEA EPS, focusing on DC grid configurations, grounding strategies, and DC/DC converter topologies. DC grid architectures, including unipolar, bipolar two-wire, bipolar three-wire, and hybrid ones, are evaluated for safety, fault behavior, EMI, weight, and efficiency. Bipolar three-wire grids show strong potential because they reduce EMI, support multiple voltage levels, and improve fault tolerance, though they require balancing converters to address load imbalance. Converter topology is addressed next, highlighting the system-level importance of choosing isolated or non-isolated designs. Isolated converters are favored for distribution to prevent fault propagation, while non-isolated converters are well-suited for balancing tasks within bipolar architectures. Finally, a grounding scheme using two high-value resistors is recommended as a balanced approach that limits fault currents while enabling reliable detection through differential measurements. Overall, the paper provides a system-level framework to guide future MEA EPS design.