The discovery of high temperature oxide superconductors has stimulated us much interest in superconductivity applications to electric machines and apparatus again. Focused on the feasibility of such superconductors for electric rotating machines or motors, here are discussed perspectives and features of many sorts of electric motors such as to be available at present.
The Japan Atomic Energy Research Institute (JAERI) is conducting Demonstration Poloidal Coil (DPC) program for investigation of superconducting pulsed-coil technology for fusion. The DPC cryogenic system is designed to cool three forced-cooled superconducting coils being fabricated in this program and the system is composed of newly developed cryogenic circulation pump, cold compressor, and vapor-cooled current leads. The installation of these componets was completed in December of 1987 and the performance test of the whole system was carried out in March, 1988. In this test, we have demonstrated that the cryogenic system meets the specifications for cooling the coil system.