DESIGN, MANUFACTURING AND COLD TEST OF A SUPERCONDUCTING COIL AND ITSCRYOSTAT FOR SMES APPLICATIONS

This paper describes the design and manufacturing of a 25 kJ supercond ucting coil as well as its cryostat and magnet support, including curr ent leads and cryogenic services, for an SMES. The coil design is base d on a minimum volume criteria. The cryostat is designed for 601 of li quid helium, and the magnet support with current leads optimised for 1 50 A. Using numerical modelling the total heat transfer into the liqui d is calcualted and minimised. the manufacturing of both components is also presented, as well as the complete system operation. Finally the paper presents the power converter topology that is controlled in opt imal PWM mode with a low switching frequency. In order to compensate d ifferent power oscillations the power converter interchanges fastly ad justable and uncoupled levels of real and reactive power.