We propose to pursue development of a new induction motor design with embedded drives enabling advanced electric drive technology to meet aircraft propulsion needs. This Phase I proposal will focus on design improvements in two areas, (1) loss and cooling, and (2) electric drive integration. The Phase I is a design effort, the phase II would continue design but also include a build and testing of components. Our concept incorporates an asynchronous (induction) style motor with embedded inverters and also incorporating two-phase semi-evaporative cooling. Ultimately targeting take-off power density of 13.4 kW/kg (and 16.9 kW/L) and around 6-7 kW/kg cruise by re-optimizing an existing record breaking design for the best trade-off between peak and continuous power density. In order to develop the above performance, the motor should not impose a high burden to the inverter.
Our design for the motor and inverter will be based on two novel technologies and related controls for electric motors. The first novel technology herein called Variable Cross-Section Wet Coils (VCSWC) pertains to a motor with record torque density and power density. The second technology incorporates an electronic pole switch control strategy (EPS). In this way the power density and efficiency will subsequently be dramatically increased. During the Phase I we will work on: motor design with enhanced power density, evaluation of the AC losses, ohmic and eddy currents properties, and cooling modes. As the culmination of the Phase I program, we will develop a nominal design for the prototype machine to be demonstrated in Phase II. The target specifications will be determined, and a nominal prototype design developed. This design will not be a build design, but will allow such a build design as the first task of a potential Phase II program.
Besides electric passenger aircraft, NASA can benefit for many applications where light weight power components are required such as smaller land-based generators, inverter type transformers, inductors, and higher frequency power conditioning equipment.
The results of this work can lead to applications related to high rpm rotating machines. Manufacturers desire to increase the efficiency, and decrease the size of their systems in order to reduce costs. Major manufacturers of high speed motors and high speed generators requiring high power density for aircraft turbo-generators, marine propulsion and portable emergency power systems.