High Efficiency Megawatt Motor Risk Reduction Activities

The High Efficiency Megawatt Motor (HEMM) is being designed to meet the needs of Electrified Aircraft Propulsion (EAP). A detailed design is in progress with changes that are informed by component testing. These component risk reduction activities are being conducted in three key areas: cryogenic cooler design, superconducting rotor coil design and manufacturing, and stator thermal management. The key objective of HEMM is to establish a motor technology which simultaneously attains high specific power (>16 kW/kg ratio to electromagnetic weight) and high efficiency (>98%) by judicious application of high temperature superconducting wire and integrated thermal management. Another important feature is to achieve the performance goals with an eye to aircraft integration constraints. HEMM is intended to be a direct drive motor or generator that can be cooled with a standard aircraft cooling loop that is used for other electronics on the aircraft. The updated design is presented highlighting changes from the preliminary design that were a result of knowledge gained through hardware tests of subcomponents. An overview of those subcomponent tests is also provided. The HEMM technology could be applied to a range of aircraft types that require megawatt level electrical power.