This article presents a simplified mathematical model of the anisotropic magnetic field dependence (AMFD) for simulating the High-temperature superconducting (HTS) Conductor on Round Core (CORC) Cables. All these simulations of HTS CORC Cable were performed based on the finite-element method (FEM) H formulation model merged into the numerical platform COMSOL Multi-physics. The simplified model of AMFD was implemented into both the 2-dimension (2D) and 3 dimension (3D) H formulation models of HTS CORC cables. Their results were studied with different conditions, such as the increasing transport current, as well as the gap angle between the superconducting tapes in a single layer. This new simplified AMFD model can give a proper approximation of the actual electromagnetic behaviours of the HTS CORC, but also establish the upper limit of the AC loss calculation, which can be fairly useful for designing future HTS CORC cables.

High temperature superconducting flywheel energy storage system (HTS FESS) based on asynchronous axial magnetic coupler (AMC) is proposed in this paper, which has the following possible advantages: the generator/motor (G/M) can be installed outside of the vacuum chamber with the torque being transferred by the magnetic coupler, and the stator liquid cooling system is not needed; the idle loss of G/M during the stage of energy maintaining can be eliminated by disconnecting the coupler from the system by the magnetic field shielding device. Up to now, there is few research on AMC for high speed application. In this paper, the performance parameters of the torque, axial force, and magnetic flux density in the middle of air-gap and at the mean radius are calculated based on finite-element model (FEM). The prototype used to update the 30 kJ/2 kW HTS FESS developed in 2014 is manufactured, and the test platform of transfer characteristics at high speed is established. The experiments at high speed are conducted and the measured results show a good agreement with the simulation results. Meanwhile the correlations between the magnetic flux density, the axial force and HTS FESS are analyzed. At last the feasibility of AMC used for HTS FESS is validated by the charge and discharge experiment. The system efficiency and technical problems are analyzed.

The miniaturization of sensors and non-contact measurement techniques is currently at the forefront of smart grid development. This paper proposes a miniature voltage sensor whose size is significantly reduced while maintaining large bandwidth and high linearity. To minimize the impact of environmental factors on measurement accuracy, a differential structure is utilized to optimize the sensor. The sensor is designed with a dual-channel measurement mode for both high-frequency and power-frequency signals, addressing issues of signal refraction and reflection due to impedance mismatch. COMSOL Multiphysics 6.2 is employed to simulate the sensor’s structural design and placement. Moreover, the experimental analysis of key parameters, such as parallel resistance and capacitance, identifies the optimal parameter combination for low-voltage distribution lines and cables of 10 kV and below. Experiments show that the voltage sensor’s bandwidth ranges from 30 Hz–200 kHz when measured through a frequency response analyzer. Finally, through the measurement carried out on the overhead line and cable, we evaluate the linearity of the sensor according to the experimental data. Specifically, the nonlinear errors of the voltage measurement for the overhead line and cable are 0.62% and 0.57%, respectively.

This paper presents the loss analysis on the saturated iron-core superconducting fault current limiter (SISFCL) for a VSC-HVDC transmission system. The numerical model of SISFCL as well as its loss calculation on superconducting parts were carried out by the finite-element method (FEM) using the H-formulation merged into the commercial package COMSOL. The SISFCL model was established for a practical 10 kV VSC-HVDC system, and the fault current situation was simulated using the PSCAD with a SISFCL. The capability of fault current limiting was verified using the analysis of electromagnetic characteristics, and the corresponding patterns of magnetic field in the iron-core were studied. During the process of fault current limiting, the instantaneous power losses in the superconducting components were studied with the increasing DC bias current. Even in a DC grid system, results proved there were considerable amounts of losses occurred in the superconducting parts, when the SISFCL encountered the fault currents.

In need of high current carrying capacity, tapes are usually assembled in a cable. There are several cables options and one of them is the YBCO stacked-tape cable. In this paper, 4 YBCO tapes were stacked and pancake coils were constructed which are the component of a toroidal superconducting magnetic energy storage system. The stacked-tape cable could improve the operating current of the toroidal magnet, therefore increase the stored energy. However, the stress experienced by the conductor will also be very high. In this paper, numerical simulations analyses of stress and strain combining electromagnetic fields and mechanical behaviors were performed to investigate the effect of the electromagnetic forces on the coil and the support structure.

Taking the advantage of quench behavior, high-temperature superconductors (HTS), such as YBCO tapes, are gradually used in the resistive superconducting fault current limiters (RSFCLs) for the direct current power system. However, due to the high cost, as well as the mechanical vulnerability, the complexity of HTS still remains. In this article, first YBCO tapes were sustained under different pressures, and then the transient characteristics of the tapes were tested under a huge pulsed current. Results show that while applying pressures on YBCO tapes, the resistance would increase significantly. Thus, a new approach to increase the quench resistance of RSFCLs was proposed, which could potentially reduce the consumption of YBCO tapes and cut down the cost.