Effect of switching frequency and number of winding layers on copper loss of an inductor

Abstract

Power inductor operating in a high frequency switching power converter experiences both core loss and copper loss. It is a common belief that the higher the switching frequency is, the higher will be the inductor loss. In this paper, we demonstrate that this is not the case. In fact the higher the switching frequency, the lower the inductor copper loss. This applies to an inductor with centre-gapped, side-gapped and spacer configurations. In the loss analysis, an optimum number of inductor turns is derived analytically to minimize copper loss incurred by an inductor with side-gapped configuration.