Aviation applications can be readily adapted from motor sports applications, since the requirements are practically identical. High power density makes the vision of electric flight with a large payload possible.
Power density (kW/kg) of the e-motor, power electronics, and housing in 2016 was still around 8 kW/kg during continuous output, and approx. 11 kW/kg at maximum power (2 minutes); thus, the technical development in the coming years will represent a considerable increase in power density.
Internal or external rotors
In contrast to internal rotors, the air gap in external rotor drives can be kept very small, since the rotor sleeve has a strong influence on the mechanical air gap. The air gap between the rotor and stator is of great importance for the surface thrust of an electrical machine.
Surface magnets with soft magnetic yoke vs. Halbach array
Greater power density through
modified rotor geometry
Smaller pole pitches
A smaller pole pitch allows for
optimized design of power electronics
A special power electronics design ensures high pole change frequencies, placing greater demands on the machine controls.
The next generation of SiC-based power modules enables
Greater integration density
Integration of motor and power electronics in one housing creates
These optimizations in aviation applications already implemented by Compact Dynamics have led to significant improvement in power density:
We believe there is further potential for optimization in
Power densities of up to 14 kW/kg and more during continuous output, and considerably above 18 kW/kg at peak performance, are certainly feasible for applications in electrical aviation, as we continue on the development path
that is set out.