Electric machines and hybrid drives for vertical takeoff and landing (VTOL) tactical air vehicles

During Phase l of this contract, PiAC conducted a conceptual design study and evaluated specific designs for a Hybrid Electric propulsion system for a VTOL aircraft requiring 50 to 250 KW of power and weighing up to 1320 pounds. PiAC identified an architecture for this Hybrid propulsion system and analyzed relevant variables against the design and its performance. The results indicated that a parallel hybrid offers a significant weight advantage over a series hybrid implementation. For Phase II, PiAC is proposing to further explore the development of a parallel hybrid drivetrain by means of a ground-based test stand supporting the modeling, integration and testing of individual components and complete subsystems of a parallel hybrid drive in the 200-kW combined power class. This approach builds on the Phase I findings and will examine an optimized approach to the hybrid drivetrain. Since the topic focus is on the drivetrain, it is foreseen that the sizing will be aimed at providing good coverage of the power range of interest. A numerical model of a representatively sized, suitable air vehicle will be used to generate power time histories which will be used to exercise the test stand and validate performance, dynamics and fault tolerance.