A hybrid-electric passenger plane
1st Quarter 2018, Electrical switching & drive systems & components
Siemens is working together with Airbus and Rolls-Royce to test a hybrid-electric propulsion system in a large aircraft. This will be a big step closer to electric aviation.
What the companies have in mind is a 100-seat passenger aircraft in which one of the four conventional turbines has been replaced by a high powered electric motor. Such an aircraft is expected to make its maiden flight as early as 2020 and serves as a technology demonstrator for the new drive system.
Dr Frank Anton, head of Siemens eAircraft, and Wulf Roscher, project manager for E-Fan X at Siemens eAircraft, discuss this revolutionary project.
What does this project mean for Siemens in view of the company’s existing eAircraft activities?
Frank Anton: Following-up on the kick-off of our partnership with Airbus in 2016, this large flying demonstrator will be a major step for eAircraft toward a hybrid-electric future. By testing the demonstrator and its electric propulsion system in flight, we will learn how to harness this disruptive innovation for aviation.
Thanks to our existing drive systems for drones and ultralight and light sport aircraft, we are already involved in aviation. Recently, we also presented a prototype motor for the CityAirbus, a flying taxi for use in urban areas.
We are now building on the experience we’ve gained during development of motors with these outputs in order to develop the first solution for a commercial aircraft: a hybrid-electric airliner that can seat 50 to 100 passengers. This development will enable passenger transport to become quieter and more sustainable.
What exactly are you planning?
Wulf Roscher: The electric propulsion systems that eAircraft has developed to date – our world-record drive system, for example – have had outputs of up to one fourth of a megawatt. But now we are developing a two MW electric propulsion system for regional aircraft that will be about eight times more powerful than the system that drives our Extra 330LE. Four to eight such motors on the wings of a regional plane could power an aircraft’s propellors or fans. In the flying demonstrator, the electric propulsion system will obtain its power from a generator that will be powered by a turbine in the fuselage. Take-off and climbing will be supported by lithium-ion batteries, each of which will have 700 kW of power.
Anton: Our intention is to replace one of the test plane’s four jet turbines with a two MW electric propulsion system in time for the maiden flight, which is scheduled for 2020. That would be the first time that such a powerful electric motor would help to propel an aeroplane. We can imagine that in subsequent tests, we will replace an additional turbine with an electric propulsion system.
Wouldn’t such a powerful drive system weigh a lot and take up an incredible amount of space? Although electric mobility has many benefits, can such a drive system be efficient?
Roscher: Thanks to the extensive amount of research we have conducted in advanced lightweight engineering and high-tech materials, we expect to be able to drastically reduce the size and weight of our drives. Although our previous record-breaking motor achieved a continuous performance output of 5,2 kW per kilogram of motor mass, we want to significantly improve on this in our 2 MW motor.
Anton: The secret recipe is not materials or topology. The kinds of extremely light propulsion systems we are talking about can be developed and built only thanks to Simcenter, a Siemens PLM simulation suite software that takes all known physical and technical effects into account. Using this technology, we iteratively build digital twins and thus virtually optimise our prototypes. This not only accelerates development, but also results in more powerful machines.
What are the roles of the project’s partners?
Anton: Airbus will be in charge of overall integration and test flights and will deliver the energy storage systems. Rolls-Royce will provide a 2,5 MW turbine and integrated generator that will supply the electrical power for our electrical propulsion system. In addition to the electric motor for the inverter, Siemens will provide the energy distribution system. I think that by partnering, three major players are building a flying demonstrator that will bring us closer to a vision of flying across Europe in hybrid-electric passenger planes.
For more information contact Jennifer Naidoo, Siemens Digital Factory and Process Industries and Drives, +27 (0)11 652 2795, firstname.lastname@example.org, www.siemens.co.za