Development of elementary technologies for 100 kWh/20 MW SMES with multipurpose applications

Several technologies are being developed to establish a 100 kWh/20 MW superconducting magnetic energy storage (SMES) pilot plant with multipurpose applications. These technologies include the design, fabrication, and testing of a SMES model coil, current leads, coil protection systems, AC/DC converters and persistent current switches. In addition, the optimization of SMES systems and the effect of onsite applications were studied. The coil was confirmed to have a high current capacity (40.53 kA), a high level of stability, sufficient mechanical strength, outstanding electric insulation, and low-resistance coil connections. Other important developments include a yttrium-based 20 kA HTS current leads, a SHe flow method to be used as an alternative quench detection system, a snubber energy direct regeneration AC/DC converter system with an efficiency as high as 96.8%, and a persistent current switch with superconducting contacts. To evaluate the SMES protection, monitoring and control systems, a direct analogy SMES simulator was also developed.