Frequency- and time-domain analysis of skin effects

Skin-effect phenomena, the reduction of a conductor effective cross-sectional area, can be evaluated analytically in the frequency domain in terms of well-known functions for simple conductor geometries. These results are usually approximated for high-frequency limits where conduction takes place predominantly within a thin skin depth. This approximation is frequently seriously in error, especially for complex time variations associated with power inverters, converters, etc. For these power applications, time-domain analyses are required. Results useful for complex time variations are developed in terms of series solutions that are particularly useful for computer analysis of power circuits. Frequency-domain results are also derived for rectangular cross-sectional area conductors, as these conductors are frequently used in power applications.