Comparison between two formulations in terms of potential for the coupling of magnetic and electric circuit equations

The 3D numerical simulation of electromagnetic systems accounting for the electric circuit equation is studied for strand conductors. Two formulations in terms of potential (A and T₀Ω) are compared and discussed. The finite element method is used to solve the magnetic equations with tetrahedral edge elements and tetrahedral nodal elements for, respectively, the A and T₀Ω formulation. As an example of application, an iron-core coil and a current transformer have been simulated. In the latter the numerical results are compared with the experimental results