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Magnetic resonance imaging (MRI) scanner consists of five major components: The main magnet, a gradient system, an RF coil system, a receiver, and a computer system for data acquisition. Gradient coils are an integral part of an MRI system, used for spatially encoding the MRI signal via modulations on the main magnetic field. In this article, we discuss the in-house design and production method of a particular gradient coil aimed as a part of a portable MRI instrument with a 1 T high-temperature superconducting (HTS) main magnet. We aim to reveal a clear path for those who want to follow.

Airbus UpNext has launched an Advanced Superconducting and Cryogenic Experimental powertraiN Demonstrator (ASCEND) project in 2021 to develop a superconducting electric aircraft propulsion system. The demonstrator system power is rated at 500 kW with the dc voltage of 300 V. A dc networks can achieve smaller footprint and improved distribution efficiency. However, fault management in dc networks is much more challenging than ac systems because: firstly, there is no natural zero-crossing of the current to isolate the fault; and secondly, the rate of rise of fault currents is often significantly higher due to lower system impedances. Resistive superconducting fault current limiter (RSFCL) is a passive device that provides protection without requiring external input, making it inherently reliable. Non-inductive bifilar pancake RSFCL coils supported by G10 former are designed and built based on ASCEND system specification. This paper will present the design of RSFCL using 2G high temperature superconductor tapes for ASCEND demonstrator. A dc fault current testing circuit is built for testing of RSFCL. RSFCL is experimentally tested from 65 K to 77 K in the sub-cooled liquid nitrogen cryostat. The current limitation and recovery time are compared for different operating temperatures. In conclusion, RSFCL using HTS tapes demonstrates effective and fast current limitation within 1ms, which significantly improves the reliability of the system.

Large-scale electric aircraft are a promising technology that could revolutionise air travel to reduce the environmental impact. Fault current limitation and interruption technology is crucial to realise the safety and reliability of the electric aircraft, in particular for large-scale electric aircraft using a DC distribution network. This article proposes to integrate a resistive superconducting fault current limiter (SFCL) with a cryogenic DC solid-state circuit breaker (SSCB) so that the SFCL limits the fault current to acceptable levels in DC networks allowing the SSCB to operate quickly and reliably. A sub-cooled liquid nitrogen cryostat, which can be controlled from 65 K to 77 K, is designed and built for the integration of SFCL and DC SSCB. An SFCL and SSCB prototype is designed and experimentally tested at cryogenic temperatures, which successfully demonstrates the ability to limit and interrupt currents at cryogenic environment.

High temperature superconducting (HTS) stacks of superconducting tapes provide a solution for all-superconducting electrical machines since they could work as trapped-field magnets. Most experiments with these stacks use pieces of tapes with relatively small areas as wider tapes are more difficult to acquire, therefore in this paper we investigate substitutions for these wider tapes to be implemented in superconducting electrical machines. With different stack architectures and substrate materials made by different manufacturers with different widths, the magnetizing effect using pulse field magnetization (PFM) would be different. To explore the differences of this effect, different stacks are tested in a modified synchronous machine designed by ASuMED under liquid nitrogen conditions. By changing the stacks of the tape and testing them under the same condition, the characteristics of the trapped flux, magnetization and demagnetization are affected, the difference is then compared to a COMSOL finite element model using an electromagnetic-thermal coupled model to investigate this effect. This paper shows the experimental setup for a PFM for HTS stacked coated conductor (CC) within an electrical machine, different stack architectures are tested and simulated, and the magnetic characteristics are compared and discussed, where the simulation and experiment agree in a certain degree, and the sectioned HTS CC stacks can proven to be useful in an electrical machine.