Resistive losses of conductors carrying SMPS current waveforms

The study of 2-D skin-effect and proximity-effect transient problems by means of a formulation based on a magnetic vector potential A and on a scalar potential φ is presented. As an application of the proposed method, the equivalent per-unit length resistance of conductors carrying typical switch-mode power supplies (SMPS) nonsinusoidal current waveforms has been evaluated. The analysis clearly reveals that it depends both on switching frequency and duty-cycle and is rather different from DC and AC sinusoidal equivalent parameters. Some examples of evaluation of proximity losses in two adjacent conductors are also provided.