Topic

Hybrid powertrain technologies comprise all of the major pieces of electrified vehicles that enable multiple energy sources to combine to propel the aircraft forward. A common example would be a system where batteries, though an electric powertrain system, assist in turning the shaft of a gas turbine engine, but there are many other topologies as well. This subtopic in general is intended to cover the range of hybridization for commercial aircraft. This year, the subtopic is focused on the subset which is described as "high power electrified aircraft propulsion (EAP)" or "high power EAP". High Power EAP technologies are aimed at enabling high percentage electrification of propulsion systems for regional and single aisle aircraft. These require power dense, components and systems that can handle 10 MW of total power or more depending on the airframe and mission design requirements. Such systems range from electric machines (motors and generators) to power electronics and devices (inverters, converters, circuit breakers etc.) to cables and connectors. Superconducting systems are of particular interest for high power EAP due to their potential for extremely high specific power and efficiencies. While significant progress has been made to date in this area, there is a need for further development in order to address the final gaps for application in the field (entry into service). Of specific interest for this subtopic call are technologies for superconducting electric machines and the cryo-compatible power electronics that support them. In the area of power electronics that work with superconducting systems, there is a specific need for optoelectronics solutions to operate at or near the operational temperatures of both the electric machines and the superconducting cabling which connect them to the rest of the system (temperature ranges from 20K-40K). Cryo-compatible power electronics solutions are sought with the following as a reference design: A total power inverter solution for a multi-megawatt devices operating at the stated cryogenic temperatures with application to a superconducting motor spinning at a steady fundamental frequency of 500 Hz to 1000 Hz, 2-5 MW total output power (can be modular) at 1.5-2.5 kV, and with ultra-low total harmonics distortion (nearly a pure sine wave). Proposed inverters are welcome, and also enabling subcomponents and technologies such as: • Cryo-compatible gate drives for Gallium Nitride (GaN) High Electron Mobility Transistors (HEMT) based power electronics • Hermetic connectors for high power, high voltage (1-3kV, 75-500A) , cryogenic motor drives (a solution here may include the entire power electronics enclosure and heat sink(s) • Active EMI filtering specific to GaN HEMT based systems to reduce filtering weight Other areas of where proposal are sought under this subtopic are: • Cryo-compatible partial discharge measurement capabilities (hardware and integrated detection system) • Light weight cryo fans for gaseous helium (possible helium/hydrogen combination) for high flow rates (50+ m^3/hr or greater) Note: This subtopic is for electric powertrain components between the electric energy source (i.e. battery or fuel cell) and the shaft (as in the case of turboprop or turbine engine shaft), focusing on superconducting or other high power but extremely power dense and efficient solutions.