The two models implement a coupled A-H field formulation in FEM, solving for H in the superconducting tapes, and for A elsewhere. The tapes are represented either by means of 2D domains or 1D thin-shells. For the second case, the current sharing algorithm is implemented as an external C-function, and it is used in an inner loop within the time-stepping algorithm.
Superconducting materials are modeled by means of a E-J power law. Voltage distribution functions allow the tapes to be powered either by source voltages or currents. Lagrange multipliers define the tapes electrical connections, for the no-coupling, all-coupling and end-coupling schemes. To ease the selection of sources and connection schemes, dedicated scripts are added to the model. They can be executed using the COMSOL “Run Method” functionality, under the “Developer” tab.