Additively Manufactured Hollow Conductors with Integrated Cooling for High Specific Power Electrical Machines

Thick winding insulation required for partialdischarge-free electric machines used for aerospace applications is challenging for the design of thermal management system (TMS). This paper presents an advanced direct cooling approach using hollow conductors with coolant flow. The proposed concept is adopted in a direct-drive fractional-slot concentrated winding (FSCW) permanent magnet (PM) motor to have access to each winding conductor. The design shows significant merits including low pressure drop, fast thermal response and low thermal resistance. Additive manufacturing (AM) is adopted to build the coils (direct metal laser sintering, DMLS) and TMS (fuse filament fabrication, FFF). With the design flexibility brought by AM, parametric analysis is carried out to search for optimum design candidates. Therefore, highspecific-power (> 20kW/kg) and high-efficiency (> 95%) design targets are achieved. By adopting Aluminum alloy and Nylon for the coils and TMS, the goal of ultra-lightweight design can be met as well.