A high-T-c superconductor material model for time harmonic numerical computations

An alternative material model for sinusoidally excited superconductors or o ther nonlinear conductors is proposed. it is based on a nonlinear power-law relation between a current density and an electric field. Since the answer to a harmonic excitation is therefore nonharmonic, usually a fully time-de pendent analysis is required. Using the finite-element method in two dimens ions, a nonlinear but harmonic analysis is defined. This is achieved by con structing an effective conductivity which models the average material prope rties during one period of the excitation. The nonlinear equation system is solved with the complex Newton-Raphson method. The obtained results agree well with more exact time step solutions. The new method is much more time effective and is not restricted to two dimensions.