Modular Test Environment for Fuel Cell-Based Electric Powertrains for Aviation: Methodological Approach of the Balis Test Fields Fuel Cell, Battery and E-Drive

The application of fuel cell technology for all-electric-aircraft is currently driving numerous research activities as a disruptive approach to achieve decarbonization of short-range and regional aircraft. For the CS-23 class, the feasibility of fuel cell-based all-electric aircraft has already been demonstrated. Recently, several attempts were communicated to upscale the technology to the CS-25 class with the goal to achieve a megawatt demonstration on ground and in flying test platforms. The aim of the BALIS test infrastructure is the experimental investigation of powertrain subsystems fuel cell, liquid hydrogen tank, battery, and electric drive in the megawatt scale on ground. Following a modular approach, the named subsystems are integrated in particular test fields, which can be operated separately or coupled flexibly via the infrastructure. This approach enables the investigation of upscaling and coupling phenomena under application-relevant load profiles. After being developed and built over the past three years, this work focusses on presentation of the test fields fuel cell, battery and e-drive as well as the corresponding high voltage electrical system of the BALIS facility. The electric coupling between the test fields is carried out with the so-called switch matrix. The switch matrix enables a flexible realization of different use cases embodied by different electric connection schemes in order to investigate the electrical interactions between the subsystems, the optimization of components and operation strategies. The methodological approach is presented and an outlook on the scope of scientific research is given.