Design and evaluation of a high power density 5 MW, 6000 RPM fully- superconducting generator

In order to reduce carbon emissions, there is considerable interest in both superconducting generators and motors to enable all-electric aircraft for transportation. This paper summarizes the results of an initial design study for a 5 MW, 6000 rpm fully-superconducting generator. Using the FEMM magnetics code and the Lua scripting language, electromagnetic optimization was performed to determine the best cases. This study also considered ac loss capability of Bi-2212 superconductors, which can operate in the 30 to 40 K temperature range, along with the associated cryogenic refrigeration requirements. Initial results show that, while machines with active weight densities of ~40 kW/kg are possible, the weight of the associated cryocoolers would be prohibitive; however, the use of liquid hydrogen makes these machines realizable. Future cryocooler development is required to get their specific weights down to ~3 kg/kW of input power.