THE DEVELOPMENT OF A SMALL POWER, HIGH TEMPERATURE SUPERCONDUCTOR (HTS) SYNCHRONOUS MOTOR

This paper presents some preliminary results and the current state of the work conducted to build a small power high temperature superconductor (HTS) synchronous motor. The work was conducted at the National Research Institute for Electrical Engineering, ICPE-CA in Bucharest (overall design, prototype buildup, superconducting coils, rotor construction), in partnership with University POLITEHNICA of Bucharest (electromagnetic field and heat transfer numerical modeling), the Institute for Research in Electrical Motors, ICPE-ME (electromechanical design, stator construction) and the National Institute for Research in Cryogenics, ICSI in Rm. Vâlcea (cryogenics). The project was funded by the the National Center for Programs Management within the framework of the National Program II. The ultimate goal of the project is to develop a prototype of a high temperature superconductor (HTS) synchronous motor, in order to explore possibilities of employing superconductivity in this area. The prototype - 4 kW at 1,500 rpm - has a HTS DC field winding (in the rotor) and a conventional AC winding (in the stator). A 2D numerical simulation was used in the design phase to evaluate the electromagnetic field and the saturable regions, with the aim at optimizing the motor design. In our approach, the rotor HTS field winding is cooled cryogenically, with liquid Nitrogen, at 65 K. The preliminary results confirm that the cooling scheme adequately provides for safe temperature limits and working conditions.