Power management control and delivery module for a hybrid electric aircraft using fuel cell and battery

Highlights: • New Power Management and Control Module for hybrid drivetrains in airplanes. • Safety increase due to redundancy and other features in fuel-cell-battery-hybrid. • Functionality demonstrated in flight. • 5 operational modes possible including recharging of battery during flight. • Major contribution to enabling emission free flight. Hybrid electric aircrafts using fuel cells and batteries are an option to reduce emissions in air travel. State of the art concepts either connect fuel cell and battery using a direct current/direct current (DC/DC) converter or as a direct hybrid. Converters are flexible to control but direct hybrids are lighter and easy to build. A new power control module is presented which is easier to control than a system with DC/DC converters and more flexible and efficient than a direct hybrid. The new control module was developed to assure high aircraft safety criteria due to its redundancy and additional safety measures. It includes the possibility to charge the battery passively and actively from the fuel cell or by recuperation during flight reducing the required battery size. The functionality of the system was simulated and demonstrated in flight. This new concept can be adapted to power different kinds of hybrid aircrafts and offers a guideline to long-term all-electric flights since it is scalable for different aircraft sizes including single-aisle aircrafts. It is additionally usable for all kind of hybrid drive trains using fuel cell and battery.