Test results of the 100 kWh SMES model coil- AC loss performance

摘要

In order to establish a technology needed for asmall-scale 100 kWh SMES device, an SMES model coil wasfabricated. Performance tests were carried out at the Japan AtomicEnergy Research Institute (JAERI) in 1996. After that, the coil wasinstalled in the Lawrence Livermore National Laboratory (LLNL)facility and tested in 1998, in collaboration between Japan and theUnited states. The AC losses measured at LLNL were in goodagreement with those measured at JAERI. It was reconfirmed thatthe coupling loss of the coil could be expressed in twocomponents: one with a short and another with a long couplingtime constant. We found out from the Hall probe signals that theloop currents with long decay times were induced in the CICconductor by varying magnetic field. These currents resulted inadditional AC loss in the coil. To develop a concept of CIC withlow AC loss, we made a sub-scale CIC conductor of strandscoated with CuNi. We fabricated a small coil out of this conductorand measured the AC loss. The measured AC loss in this coil wasabout 1/6 of that in the SMES model coil conductor per strandvolume. Thus, the CuNi coating of the strands was demonstratedto be effective to reduce the AC loss in the coil. 2000 ElsevierScience Ltd. All rights reserved.