Low-calorie, high-energy generators and motors

Building on prototype motors and generators incorporating low-temperature superconductors, development of high temperature superconducting (HTS) counterparts is well along in Japan and the United States. In this article, the basic approach and principles of a superconducting AC synchronous generator or motor are described, and then the merits of using HTS field windings in their construction are assessed. Machines employing the early lower-temperature as well as the more recent high-temperature superconductors are discussed next. Finally, an update is provided on worldwide activities on developing a commercial generator and large motor utilizing superconductor windings.