HYPESS: Hybrid Power Packs with Innovative Energy Management and Energy Security System for Urban Air Mobility Applications

Electric vertical take-off and landing aircraft (VTOL) have the potential for providing fundamental relief in urban areas, significantly decreasing shipping times, and promoting completely new concepts in the fields of logistic and passenger transport. Providing energy for these aircraft is still a key challenge. Battery systems offer high performance but are limited in terms of range, while fuel cell systems can provide large amounts of energy but only offer limited short-term peak performance. Only a combination of both technologies can reliably cover both the high performance requirements of the take-off an landing phases and the energy reserves required for cruising.

Within the scope of the HYPESS project, the Fraunhofer Institue for Transportation and Infrastructure Systems IVI is developing an innovative hybrid energy system for electric VTOL aircraft used in the field of Urban Air Mobility. The aim is to create a powerful, reliable and fully emission-free energy supply system that overcomes the limitations of current battery-electric aircraft and paves the way for future safe and sustainable aviation.

Hybrid energy system combining a battery and fuel cells

One of the project results will be a modular hybrid power pack consisting of a high-performance traction battery and a modern hydrogen fuel cell system. An intelligent energy management system (EMS) for controlling the power pack will also be developed. It manages the the energy flows between the drive train and the power pack components so that maximum efficiency and low degradation of the system components are achieved. 

The EMS is complemented by aconcept for an energy security system (ESS) that ensures precise and fail-safe flight energy supply. The ESS analyzes the current operating status, predicts future load requirements and learns recurring patterns in order to detect and alleviate critical situations at an early stage. 

Simulation, modeling, and AI-based optimation approaches

In terms of technology, HYPESS pursues a comprehensive and data-driven approach. At the start of the project, a complete specification sheet is created containing all relevant technical, regulatory, and operative requirements. At the same time, several realistic reference missions representing different operating scenarios are defined, from urban short-haul flights to logistics applications in a more regional context. In addition, comprehensive meteorological data analyses were used to determine how different weather conditions affect the performance and availability of the systems. The IVIsion simulation environment serves as basis for optimizing the battery and fuel cell operation. IVIsion will be improved within HYPESS so that it will be capable of mapping the complex performance profiles of VTOL aircraft.

In the simulation and concept phase, battery and fuel cell systems will be developed with a special focus on and error and failure scenarios. These models allow inducing and analyzing critical operation states before they occur in the live system. Additionally, a variety of modern AI approaches such as reinforcement learning and deep learning will be evaluated for their potential to make the energy management system self-learning and adaptive in the long term. At the same time, the actual core components – a high-performance battery system and a commercially available fuel cell system – will be acquired and the power pack assembly will be prepared for.

Contribution to safer, more sustainable UAM energy systems

The HYPESS system allows fully emission-free flight and thus directly supports the decarbonization of aviation. The intelligent control of energy flows ensures that the batteries and fuel cell systems are operated gently, which increases their lifespan and saves resources. Simultaneously, Urban Air Mobility makes a general contribution to relieving inner-city traffic infrastructure and offers new options for the quiet, locally emission-free transportation of passengers and cargo.

Mit diesen technologischen und ökologischen Ansätzen schafft HYPESS die Grundlagen für eine nachhaltige, sichere und wirtschaftlich attraktive Luftfahrt im urbanen Raum und setzt wichtige Impulse für eine klimafreundliche Mobilitätsinfrastruktur der Zukunft.