Different types of quasistationary formulations for time domain simulations

For many practical examples in electromagnetics, quasistationary approximations to the full set of the Maxwell equations are valid. Applying such approximations reduces the level of mutual coupling between the separate equations and leads to different sets of differential equations for the specific case. Based on the resulting subsets of the Maxwell equations, numerous formulations in terms of fields and potentials can be obtained. As the type of differential equation is changed due to the approximation in general, appropriate time-integration schemes need to be selected for the numerical solution of the specific problem. An overview of existing quasistationary formulations is given while a simple test model is used to compare the different formulations.