Design Study on Additive Manufacturing Technologies in Permanent Magnet Synchronous Machines for Electric Aircraft

This paper describes the use of Additive Manufacturing (AM) technologies in permanent magnet synchronous machines (PMSM) for electric aircraft. Due to economic aspects and government restrictions, conventional manufacturing technologies like punching reach their limits when aiming for fulfilling future requirements. In the past years, AM has become a more and more relevant technology. In this paper, we present an investigation on how AM can be used in order to improve electric machines for electric flight propulsion. More precisely, the aim is to obtain an increasing torque and power density. Nevertheless, giving a brief overview of the feasibility of AM in electric aircraft is focused more than discussing technical issues in detail in this paper. The research starts with an extensive analysis on the current state of research of AM on electric machines and an evaluation of the degree of maturity. Moreover, geometric approaches for the rotor and the winding, which can only be built by AM, are pointed out and will be evaluated. Therefore, the winding and the rotor are modified. This results in lower ohmic loss density and lower eddy current loss for the winding as well as in higher torque density due to the decreased rotor leakage flux. So finally, the power density is increased which is crucial for flight propulsion. In summary, the huge potential of AM in all-electric aircraft is presented and performance improvements are quantified in this paper.