Development of MJ-class HTS SMES for bridging instantaneous voltage dips

MJ-class HTS SMES has been developed for bridging instantaneous voltage dips using newly-developed Bi-2212 cable. The developed Bi-2212 wire for SMES coils achieves high-performance conductive characteristics that do not deteriorate in high magnetic fields beyond 10 T, which enable compactly arranged SMES coils to be operated in a high magnetic field, and SMES coils of the Bi-2212 wire can be adequately insulated due to a high temperature margin. Therefore it is possible for the SMES coils to enhance dielectric strength and output power. The insulating, cooling and conductive characteristics of 4 unit coils (Outer Diameter: 700 mm, Height: 127 mm, Stored Energy: 90 kJ) were checked under a variety of conditions. Moreover, fundamental performance tests were done on bridging instantaneous voltage dips, using a 125 kW resistance and 50 kW motor as imitation loads. Testing showed that the HTS SMES operated reliably. Up to the present, 11 unit coils (Outer Diameter: 700 mm, Height: 390 mm, Stored Energy: 560 kJ) have been stacked and tested.