3D transient magnetic modeling of braking torque in a rotating conducting disc

This paper describes a combination of methods for three-dimensional transient magnetic field simulation of eddy currents including movement using the finite element method. The differential equations and boundary conditions are given to ensure the uniqueness of the potentials. The solution uses various regions and formulations. The governing equations are given in differential form. The method of interfacing conducting regions, in which an electric vector and magnetic scalar potential are used, to eddy current free regions, in which a magnetic scalar potential is used, is presented. This method is known as the T-U formulation. In the literature, the A-V formulation is usually preferred to the T-U formulation for eddy current applications. This paper provides an example well suited for the T-U formulation. The solution is then examined specifically regarding the time stepping and meshing criteria. The implemented solution results in a reasonable size set of equations and also provides numerical stability.