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Bottom-up synthesis based on site-selective atomic layer deposition is a powerful atomic-scale processing approach to fabricate materials with desired functionalities. Typical selective atomic layer deposition (ALD) can be achieved using selective activation of a growth area or selective deactivation of a protected area. In this work, we explored the site selectivity based on the difference of the inherent surface reactivity between different materials and within the same materials. By sequentially applying two site-selective atomic layer deposition, the ALD Pd catalyst is spatially confined on ALD SnO

The resistive-type superconducting fault current limiter (R-SFCL) is simple in configuration, near zero impedance at normal state, and can be quickly triggered by the fault current. So, it is a possible solution to suppress the fault current in the power grid. In this paper, the design and development of a 220-kV R-SFCL were reported. The core component of it is a module constructed by 128 bifilar coils. The bifilar coils are connected in series and parallel to form the module according to the application requirements. The bifilar coils are made of 12-mm-wide steel-stabilized 2G tapes, while 16 bifilar coils are connected in parallel to form a sub-module and 8 sub-modules are connected in series to form the module. For this fault current limiter, 10.75-km 2G tapes are used in total, and the resistance of the R-SFCL module is 4.5 Ω at 300 K. Besides, the half-size sub-module and the cryogenic insulation support (CIS) are developed and tested.

Balancing interfacial stability and Li

A Rogowski coil based sensor for current measurement in a cryogenic environment and results of its application for paralleled high temperature superconducting (HTS) coil current sharing are presented. The current sensor consists of a Rogowski coil and an integrator, where the coil output voltage is proportional to the derivative of primary current and the integrator transfers the differentiation to normal state. The Rogowski coil has promising applicability at cryogenic circumstance because its body is made of low temperature materials. The integrator ensures a large bandwidth with feasible magnitude, which is vital for dynamic current measurement during the quench of the HTS coil. The proposed current sensor is used for current sharing measurement of two paralleled Bi2223 HTS coils, and the experimental results show that the measurement precision is better than 0.5%.

The I–V characteristic of a superconductor is generally described by power-law, in which the superconductor with a high n value transfers quickly from superconducting state to the normal conducting state. With a high transport current, in the low n value area, flux flow voltage becomes lower than in the high n value area, so that the transient characteristics strongly affect its stability. Based on those properties, we propose a new hybrid conductor which is made of low temperature superconductor (LTS) and high temperature superconductor (HTS) with concentric configuration in which the HTS coat is located outside of the LTS core. According to their power-law models, the modified adiabatic and dynamic stability criteria are qualitatively obtained by taking account into not only their critical currents but also n values. As a result, the new hybrid conductors have potential applications with higher engineering current density and improved stability.

High temperature superconducting (HTS) cable is one of important apparatus in future smart-grid. Direct current (DC) HTS cable can provide secure and reliable transmission of electric power at the gigawatt level with several hundreds of kA and kV. Since the magnetic field of cable seriously degrades the critical current of HTS superconductor and then the current capacity, modern power converters often introduce alternating currents (AC) at other frequencies even filters reduce the magnitude of those ripple currents which resulting into ac loss since systems used to convert AC to direct current (DC) produce some current variations which are usually at frequencies of multiple power frequency. In order to reduce this loss, unlike the conventional uniform current design in AC HTS cable, a novel approach is proposed for minimizing the loss as small as possible by adjusting the inductive reactance of each layer so that the ratios of AC current amplitude to critical current are always same in layers. The magnetic field distribution and critical current are simulated by finite element method (FEM). The calculations show that the new approaches can reduce ac loss, improve efficiency, which are potential for DC current transmission HTS cable application.