We have studied a 10 MW class fully superconducting synchronous machine for direct-drive wind turbine generators. This machine has been designed using two kinds of superconducting wires. Multifilament wires have been used for armature windings. The DC field coils of the machine rotor are made of HTS tapes. Electromagnetic design of the generators has been carried out by FEM analysis. Analysis results show that 10 MW output is achievable with less use of HTS tapes than wind turbine generators having superconducting field coils and copper armature windings. Then, calculated AC losses are low.

The newly developed radioisotope-free technique based on magnetic nanoparticle detection using a magnetic probe is a promising method for sentinel lymph node biopsy. In this study, a novel handheld magnetic probe with a permanent magnet and magnetic sensor is developed to detect the sentinel lymph nodes in breast cancer patients. An outstanding feature of the probe is the precise positioning of the sensor at the magnetic null point of the magnet, leading to highly sensitive measurements unaffected by the strong ambient magnetic fields of the magnet. Numerical and experimental results show that the longitudinal detection length is approximately 10 mm, for 140 μg of iron. Clinical tests were performed, for the first time, using magnetic and blue dye tracers—without radioisotopes—in breast cancer patients to demonstrate the performance of the probe. The nodes were identified through transcutaneous and ex-vivo measurements, and the iron accumulation in the nodes was quantitatively revealed. These results show that the handheld magnetic probe is useful in sentinel lymph node biopsy and that magnetic techniques are widely being accepted as future standard methods in medical institutions lacking nuclear medicine facilities.

This paper evaluates the electromagnetic characteristics as to two types of superconducting motors: one is the superconducting motors adopting high-temperature superconducting field coils and copper armature windings; and the other is fully-superconducting motors, which have high-temperature superconducting field coils and MgB₂ superconducting armature windings. Analytical formulas and FEM are employed for the designs of 1.5-, 3.0-, and 5.0-MW motors. We consider how to reduce ac loss in MgB₂ winding structure as well. The analysis of our results, which was conducted mainly over output density and efficiency, suggests that the adoption of superconducting motors is more realistic in realizing electrical aircraft propulsion system in terms of higher output; the analysis results show that the fully-superconducting motors have a potential to reach over 16 kw/kg.

This paper describes and discusses fully superconduct-ing motors (FSCMs) for electrical aircraft propulsion systems. The FSCM structures have a potential to reach over 20 kW/kg thanks to air cored structure and higher current density coils while perma-nent magnet synchronous motors reached 5 kW/kg. We designed 3 and 5 MW FSCMs with YBCO field coils and $\rm MgB_2$ armature wind-ings. The FSCM output density is aiming to achieve over 20 kW/kg. To satisfy the output density, we considered back iron thickness and magnetic flux leakage with FEM. The design results show that an output density of the 3 and 5 MW motors reached 19.4 kW/kg and 25.2 kW/kg, respectively. Also, magnetic flux leakage at a distance of almost 100 mm from the motors was on the order of tens of mT.

A roadmap document for high-temperature superconductivity (HTS) in the electric power sector, 2015-2030, was developed by the signatories to an International Energy Agency (IEA) Technology Collaboration Program for “Assessing the Impacts of High Temperature Superconductivity on the Electric Power Sector” to outline the current state of the industry development of HTS devices and what steps could be taken to reach market maturity. The document highlights trends and drivers in the electric power industry that could potentially enable HTS devices to be energized in the grid. Challenges and needs are discussed for wire, cryogenics, cables, fault current limiters, transformers, superconducting magnetic energy storage, generators, and transformers. The roadmap also outlines technology readiness levels for electric grid applications. While the roadmap serves as a useful document to help inform the industry, it is a living document that will be regularly updated due to the continuous HTS technology progress/development.