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High-temperature superconductors (HTS) exhibit hysteresis, which is the main cause for losses in the subcritical domain. This behavior is well predicted by Bean's critical-state model, which is a subset of the classical Preisach model. We present a paramet ...
We use a dual channel digital lock-in to perform electrical measurement of AC losses at power frequencies. A DC magnetic field between 2 and 400 mT is applied with a varying angle from parallel to perpendicular to the tape surface, thus having a complete v ...
Transient stability investigations consist of studying the rotor oscillations of generators (electro-mechanic oscillations, 0.1-2 Hz) after the occurrence of a fault of large amplitude, e.g. short circuit. The goal is to indicate if the generators are capa ...
The use of HTSC tapes as main components in future power applications requires better understanding of their AC loss behaviour. Previous studies have lead to conclusions that eddy current loss is a significant loss factor at high frequency in self-field. I ...
The E-J power law as electric characterization of the HTS material in Finite Element computations has shown good agreement with measurements of field-dependent crtical current density and losses due to transport current. We use this technique to investigat ...
We have made a software electromagnetic simulation of eddy current effects in Bi(2223)Ag sheathed tapes with applied AC transport current in a broad frequency range. We have used simple models of monocore and multicore tapes. Calculated is the power distri ...
The classic Preisach model is used to describe a general hysteretic behaviour, and as most nonlinear systems, its output contains higher harmonics. A Fourier analysis of a specific class of weighting functions for the Preisach model relates some free param ...
A digital lock-in amplifier has been used to perform V-I time series acquisition when transport currents with amplitude above Ic are driven through Bi-2223 tapes. The current waveform is triangular, sinusoidal or with arbitrary shape, and is applied for se ...
We study the energy barrier for flux entry of a geometric origin in type-I superconducting strips using magneto-optical observations of the flux structure. The magnetic field is applied perpendicularly to the broad surface and, optionally, a dc current is ...
We present a parametrised Preisach-type model that describes the hysteresis exhibited by the high temperature superconductors (HTSC); hysteresis is the main cause for losses in the subcritical domain. The parametrised model, in combination with electrical ...
