Test results of the SMES model coil-pulse performance

A model coil for superconducting magnetic energy storage (SMES model coil) has been developed. To establish the technology needed for a small-scale 100 kW h SMES device, a SMES model coil was fabricated and tested in 1996, The coil was successfully charged up to about 30 A and down to zero at the designed magnetic-field ramp rate for the SMES. Alternating current (AC) losses in the coil were measured by an enthalpy method. The results were analyzed and compared with the test results from a short sample. The measured hysteresis loss is in good agreement with that estimated from the short sample results. It was found that the coupling loss of the coil could be described as consisting of two components with different coupling time constants. One has a short time constant of about 220 ms, which is in agreement with the test result of a short conductor. The other has a long time constant of about 30 s, which was not expected from the test results for the short sample. (C) 1999 Cryogenic Association of Japan. Published by Elsevier Science Ltd. All rights reserved.