The Future of Advanced Air Mobility

Smart, Light, Compact Motor and Controller Improve Hydrogen-Electric Propulsion

Electric motor specialist Aeristech is establishing a new development and test facility in the UK. In a December 18 announcement, the company also confirmed it is joining the government-backed HyFlyer II sustainable aviation program, with its electric motors having been selected to form part of the hydrogen-electric propulsion systems ZeroAvia is developing to convert turbine-powered aircraft.

Aeristech, which has experience in the electrification of automotive superchargers, has been awarded £2.7 million ($3.5 million) in government funding from the Aerospace Technology Institute, which this week also awarded ZeroAvia a £12.3 million grant for its HyFlyer II work. The expanded Aeristech facility at Leamington Spa in the Midlands region of England will create 60 skilled jobs.

The company will provide ZeroAvia with its 25 kW fuel cell compressor technology to support the California-based start-up’s aim of having a hydrogen-electric 19-seat aircraft ready to enter service in 2023. Aeristech says its breakthroughs in motor controller technology have allowed it to develop stators that are much lighter and more compact while delivering the same power as equivalent systems.

The company’s complete electric compressor, consisting of a controller, motor, and wheel impeller, will be integrated with ZeroAvia’s fuel cell stack to form a complete hydrogen hybrid electric powertrain. It developed the power-dense electric motor mainly from its extensive work on cars, trucks, and also ships, which has seen it eliminate bulky wires and other hardware.

“We put in compressed air to interact with the hydrogen feed [from ZeroAvia’s fuel cells] and our compressor will respond to signals in their control methodology,” Aeristech managing director Duncan Kerr told FutureFlight. He explained that the company’s controller manages the generation of electric energy by switching semi-conductors on and off rapidly, but only doing so at the speed actually required by the motor. He estimated that this rate is ten times slower than for other systems, resulting in less stress on components and more operational flexibility.

The Aeristech team is now starting a feasibility study to finalize how to supply compressed air to ZeroAvia's fuel stack. By around the end of 2021, it expects to be close to producing a prototype unit for the HyFlyer II program. 

Aeristech said that, in the next few months, it expects to announce other propulsion partnerships for aircraft applications.