Committee:

Dr. Lukas Graber, ECE, Chair , Advisor

Dr. Sastry Pamidi, Florida State, Co-Advisor

Dr. Maryam Saeedifard, ECE

Dr. Santiago Grijalva, ECE

Dr. Thomas Habetler, ECE

Dr. Mitchell Walker, AE

Abstract:

Traditionally, liquid nitrogen has been the standard cooling medium (cryogen) for operating superconducting power applications. However, gaseous cryogens, which have several bene ts over liquid cryogens, are recognized as promising cooling media for future superconducting power systems. The main bene ts of gaseous cryogens are lower asphyxiation hazard, wider operating temperature range, which enables superconductors to be operated with higher current density, and lower pumping e ort, which allows the use of longer superconducting cables and the integration of multiple superconducting devices with a single refrigeration system. Although many advantages are gained by using gaseous cryogens, the major challenges for the widespread use of gas-cooled superconducting power applications are lower heat capacity and lower dielectric strength. Studies addressing means for compensating the low heat capacity issue have been reported in the literature. However, no study has thus far reported any feasible solutions for the low dielectric strength challenge associated with using gaseous cryogens. This dissertation focuses on developing tools to study and discovering methods to improve the dielectric strength of gaseous cryogens for medium- and high-voltage superconducting power applications.