Research database

Transportation Electrification is EU goal and in aviation the propulsion technologies evolve towards hybrid-electric systems to cope with lower emissions and improved reliability and maintenance costs. Hybrid-electric architectures are based on a gas-turbine driven electric generator that provides power supply to electric drives coupled with the aircraft propellers and this allows distributed propulsion to maximize the thrust efficiency and minimize the aerodynamic resistance. In hybrid-electric aircrafts the electrical design must deal with fault tolerant requirements and high currents due to the relatively low value of the on-board voltage. Multi-phase generating systems represent a unitary solution for the needs of safety-critical and high current applications. The intrinsic redundancy makes multi-phase arrangements compliant with the reliability standards and operational needs; spreading the overall power among multiple phases allows using faster semiconductor devices to achieve improved power quality and efficiency. Modules based on independent single-phase or three-phase units feature higher fault tolerance as, in case of fault, the disconnection of a converter module allows maintaining operation at reduced performance. However, if a fault occurs in the machine, the possibility to keep safe operation is still an open challenge. Further, the control algorithm must detect converter or machine faults and adopt a strategy to minimize reduction of the drive performance. The project aims to develop scientific knowledge and viable solutions for fault tolerant generating systems in hybrid-electric aircrafts. Focus will be on multi-phase generator system with working capability in presence of one or more faults. This objective will be pursued by means of design methods and simulation models devoted to the following: Università de L’Aquila will be in charge for designing a multi-phase generator with IPM rotor whereas Politecnico di Torino will investigate a lower TRL generator arrangement based on superconductive windings excitation to avoid permanent magnets and improve the power density; Università Roma Tre will be in charge for setting up a multi-level AC-DC converter with high tolerance of faults in power semiconductors and Università di Bologna will develop a control algorithm for detection and management of fault conditions within the generating system. The Units will share a common approach in terms of multi-phase architecture, fault-detection and fault-management methods. The project includes experimental activities devoted to validation of the design and simulation methods. The Units include electric, electronic, mechanical and aerospace engineers, and experimental physicist to deal with all the project aspects. National/international companies expressed their interest on the impact of the expected results.