Harmonic boundary conditions for circular inclusions and their coupling to external circuits

The effect of the magnetic field in a homogeneous subdomain of a finite-element model is simulated by an analytical expression imposed at its boundary. In the case of a stranded or a solid conductor cross-section, the coupling to an external circuit is considered. The hybrid finite-element harmonic-boundary equivalent-circuit approach offers the designer a powerful simulation tool, yielding models attaining the same accuracy when compared to pure finite-element models but requiring less (by a factor of 10) computation time. The relationships with the boundary-element method and impedance boundary conditions are established. The application of the methods proposed for a cable model illustrates the benefits of the proposed approach