Background and Motivation
Alternating current (AC) losses are a major source of energy dissipation in superconducting materials and coils. They cause unwanted heat generation, which can compromise cryogenic stability and reduce overall system efficiency. Understanding the mechanisms of these losses and predicting them accurately are therefore essential for the reliable design and optimisation of superconducting devices.
Modelling and Simulation
We developed finite element models to study AC losses in high-temperature superconducting (HTS) tapes and coils under different operating conditions. Both 2D axisymmetric and 3D FEM models were used to calculate current density distribution, magnetic field variation, and loss behaviour during current ramping.
The models include hysteresis, coupling, and eddy current losses, and use a moving-mesh method to simulate realistic coil excitation and transient electromagnetic conditions. Parametric studies were carried out to examine the effects of tape width, frequency, and flux diverter structure on total AC loss. The simulation results help to understand the main loss mechanisms and support the optimisation of coil geometry and winding design.
