Multiport Inverter Implementing Multiobjective Vector Modulation for Direct Integration of Battery, Fuel-Cell, and Electric Motor in Electric Aircraft

This article proposes a power distribution system tailored for the Pipistrel Velis electric aircraft. It uses a multisource inverter (MSI), integrating a battery energy storage system and hydrogen fuel-cell range extender to power the electric motor. A three-phase three-level T-type inverter is chosen for its ability to handle two independent dc power sources and an electric motor. However, managing power transfer between the energy storage systems and motor poses a challenge. To address this, a multiobjective vector modulation (MOVM) strategy is introduced. This strategy aims to maximize fuel-cell output power while maintaining constant motor power, even under varying conditions. It involves separating converter output vectors and introducing controllable power transfer angles. This article describes this strategy and presents a method for calculating optimal power transfer angles. The method is compared with other solutions using simulations and experimental testing which validates the method under conditions similar to a typical Pipistrel aircraft flight profile.