Design and Comparison of Direct-Drive and Geared High Specific Power Permanent Magnet Motors for Aerospace Applications

Electrical machines are key enablers of hybrid/electric propulsion in aerospace applications. This is attributed to the following advantages: (i) full or partial elimination of fossil fuel which is reflected on emissions and less reliance on fossil fuel resources, and (ii) noiseless system. On the other hand, current electric motors are not competitive in terms of the machine Specific Power (SP) as well as efficiency. The targets for SP are double or triple the state-of-the art. In this paper, potential designs for direct-drive as well as geared topologies enabled by Additively Manufactured (AM) coils Fractional Slots Concentrated Windings (FSCWs) with integrated heat pipes will be discussed and compared. On the rotor side, the considered designs are configured with Halbach array Permanent Magnet (PM) rotor. As a result, it will be shown that these designs provide significant encouraging results towards the global trend of magnifying electric motors SP.