High Power Density Dual Rotor Permanent Magnet Motor with Integrated Cooling and Drive for Aircraft Propulsion

There is a critical need for electrification of transportation systems. The proposed technology enables the development of very high-power density permanent magnet motors, which when coupled to an integrated SiC drive allows for an overall specific power beyond 12 kW/kg. The proposed concept relies on the tight integration of a high-power density dual-rotor permanent magnet motor, high power density SiC power converters and a shared closed loop cooling system rejecting the heat in the propulsion ducted fan air stream. The proposed motor is based on a dual-rotor configuration using permanent magnets forming ideal Halbach arrays allowing for high magnetic loading without the need for iron. The permanent magnet rotors are based on “continuous flux directed” magnets (PM-360™) currently under development at AML and an air-gap stator with direct liquid cooling allowing for high electric loading and unprecedented specific torque and specific power. The heat is removed by a closed loop of liquid shared by the motor and power converter. The heat is rejected in the propulsion air stream. The integration of the motor and power converter will help to achieve very high-power density which is paramount in aircraft application. A high efficiency three-level SiC inverter will be developed with high switching frequency (>25kHz). By adoption of SiC device with the proposed intelligent gate driver technology as well as multi-level topology with active surge voltage canceler, the inverter can be integrated into the motor enclosure.