Development of high temperature superconducting power transformers

High temperature superconducting (HTS) transformers offer many benefits over conventional power transformers for utility applications, including emergency operation to twice rating without loss of transformer life, halved size and weight, elimination of oil as a fire and environmental hazard, reduced leakage reactance, and a possible fault current limiting feature for improved system performance. This paper briefly summarizes work in the field and describes various HTS transformer design approaches (including one approach shown in Fig. 1). We discuss the various design, operation, and cost issues associated with the development and utility acceptance of this new technology.