Safran Tests Hybrid-Electric Turboprop

Safran has run a hybrid-electric turboprop engine under the European Union’s Clean Sky 2 research program.

The modified Tech TP technology demonstrator has completed ground tests at Safran Helicopter Engines in Tarnos, France.

Based on Safran’s Ardiden 3 turboshaft engine, Tech TP is a demonstrator for a 1,700-2,000-shp turboprop to power aircraft with up to 19 seats. The more-electric variant has been developed under Clean Sky 2’s Achieve project—for Advanced Mechatronics Devices for a Novel Turboprop Electric Starter-Generator and Health Monitoring Systems—led by the UK’s University of Nottingham.

The project has developed a more powerful electric motor-generator that is combined with its power electronics in a single unit that has been integrated with the Tech TP’s propeller and accessory gearbox. The 25-kVA motor-generator has been developed with UK electro-mechanical systems specialist Nema and the power electronics with France’s Power System Technology.

Allowing the propeller to be driven by a battery and electric motor enables new operating modes, such as taxiing without using turbine engine power and providing in-flight assistance to the turboprop. This reduces fuel consumption and emissions as well as noise, Safran says. With a power density greater than 10 kW/liter, the system will also deliver more than 20 kW of power when operating as a generator.

Achieve is a precursor to a new project to develop a hybrid-electric propulsion system for regional aircraft (HE-ART) under Europe’s Clean Aviation program, the follow-on to Clean Sky 2. Led by Rolls-Royce Deutschland, the €60 million ($64 million) HE-ART project will demonstrate a powerplant that develops from 2.15 megawatts (2,880 shp) of power with the electrical system up to 2.85 megawatts with both thermal and electric power sources driving the propeller gearbox. The demonstrator will be based on Safran’s 2,500-3,000-shp Aneto turboshaft.

Also under Clean Sky 2, the e-Maestro project has studied a hybrid-electric version of General Electric’s Catalyst turboprop to power 19-seat airliners. The hybrid-electric investigations are a sub-package within the larger Maestro project, which has contributed to development of the 850-1,650-shp Catalyst.

The e-Maestro effort also is a precursor to a new project under Clean Aviation. Amber (for Innovative Demonstrator for Hybrid-Electric Regional Application) is a €34 million project led by GE’s Avio Aero which will develop a 2.25-megawatt system based on the Catalyst that will be continuously boosted by electrical power from hydrogen fuel cells.