Pulse Magnetization Studies on Partially Slit Second-Generation High-Temperature Superconductor Tape

Laboratory experiments were performed to study the second-generation (2G) YBCO high-temperature superconductor (HTS) partially slit tapes (PST) energized using pulse magnetization. The PST can be formed into a loop configuration without resistive splices. Following the decay of the pulsed magnetization transients, the currents flowing in the PSTs are persistent. This paper investigates the PST's performance as affected by the changes in the pulse energy, presence of iron shielding, use of multi-PSTs, and different pulse charging techniques, at 77 K. One conclusion from the experiment is that the PST's have the capability to activate, deactivate, and even reverse the magnetic fields by adjusting the polarity and magnitude of the pulse fields, in just a few milliseconds. This capability to quickly decrease the current in the 2G HTS tape can be used to protect the system in the case of a fault. In addition, the use of persistent tape eliminates resistive joints/splices, which can cause quench. This configuration also inherently protects the tape itself by limiting the current carrying capacity of the tape. These features have great potential to transform HTS 2G technology for high power motors, generators, and magnet applications.