Speaker
Description
The T-A formulation of Maxwell’s equations in the magneto-quasistatic approximation is a popular approach for simulating the electromagnetic behavior of high-temperature superconducting (HTS) wires, cables, and coils. The mathematical formulation of the model is based on the magnetic vector potential A (B=curl(A)) for calculating the magnetic field in the entire simulation domain and of the current vector potential T (J=curl(T)) for calculating the current density in the superconductors.
In this contribution, we discuss the application of the T-A formulation to the case of rotating coils in an external static magnetic field. This requires the T-part that describes the induced current density and the electric field in the moving conductors to be expressed in the rotating frame. The critical point is the formulation of the coupling relationship between electrical parameters on the boundary of the A- and T- parts in order to guarantee the correct energy flux continuity.
First, the model is validated by a comparison with an analytical solution available for the case of constant resistivity and then by a comparison with the results obtained with the H formulation for the equivalent case of a static coil in a rotating field. Then, the model is applied to cases of increased complexity, including the case of transport current and of coupling with an external electric circuit.
