This conference paper was submitted for presentation at the NAFEMS World Congress 2025, held in Salzburg, Austria from May 19–22, 2025.

Abstract

We present an approach that allows accurately simulating hybrid electric aircraft by combining systems level simulation tools with electronics simulation tools through co-simulation. Hybrid electric aircraft offer a way to reduce the environmental impact of the aviation industry. They promise to reduce greenhouse gas emissions significantly, while also reducing noise emissions specifically during ascent and descent close to population centers. The development of hybrid electric aircraft requires being able to model and predict their behavior across different physical domains---aerodynamics, mechanics, thermal dynamics, and electronics. Relevant time scales range from a flight mission duration of several hours down to the sub microsecond switching dynamics of the battery converters. To be able to simulate the different physical domains as accurately as possible, we use dedicated modeling tools for the system level aspects (Simcenter Amesim (SC-Ame)) and the power electronics aspects (HyperLynx AMS (HL-AMS) and PartQuest Explore (PQE)). In order to be able to investigate the coupled behavior of the different domains across the whole range of relevant time scales, we have set up a co-simulation toolchain which couples the aircraft model in SC-Ame as the primary tool with the model of the (power) electronics in HL-AMS as secondary tool. The electronics model is created in PartQuest Explore for early concept exploration, but can be automatically converted to Hyperlynx AMS for further physical (PCB) design development and verification. The electronics models can support SPICE as well as the IEEE/IEC Standard VHDL-AMS. This methodology supports a 'œsupply chain' for device models, where component manufacturers can provide full electrical and package thermal simulation models that their customers can assemble into functional schematics of their applications. Using this co-simulation approach has enabled us to investigate effects which could not be simulated using any of the tools alone. We have modeled the power electronics that provide a stable voltage from batteries to the airplane e-motor at a sub microsecond resolution, revealing the dynamics in the individual DCDC converters. This enables the system level simulation to correctly assess e.g. power losses in the converters and actual DC output voltage. On the other hand, the system level simulation of flight dynamics and battery discharging behavior provides information to the electronics simulation necessary for simulating the exact operation of the battery management system and the converters. In summary, our co-simulation allows us to accurately simulate aircraft behavior, including the failure of specific electronic components under certain control algorithms. This capability enables us to validate mitigation measures, such as component redundancy and failure handling software, ensuring aircraft safety even in the event of component failures.