Stator prototype for a high current density electric motor: Assembly, evaluation, and testing

In the pursuit of electric aviation for reduced environmental impact, electric motors and associated supporting drive systems and coolant loops are required to have high power density (kW/kg). Higher overall motor system power density can be achieved when operating with a higher current density (A/mm²) that can be passed through the wires in the stator. The maximum current density is thermally limited, and therefore an approach of high-performance cooling integrated into the motor stator is explored here. A stator section prototype is constructed, evaluated, and tested to the maximum current density at which failure occurs. Novel design features include additive manufacturing of the stator having two-phase cooling in microchannels that are closely integrated with Litz wires that form the stator coils. This study successfully reduces risk with both the thermal performance and the fabrication quality. This outcome sets the stage for the fabrication of a full motor with this type of construction.