Inductor winding loss owing to skin and proximity effects including harmonics in non-isolated pulse-width modulated dc-dc converters operating in continuous conduction mode

A general expression for winding loss (copper loss) including harmonics for an inductor carrying periodic non-sinusoidal current is presented. The skin and proximity effects are taken into account. Expressions for amplitudes of inductor current harmonics are derived and illustrated as functions of duty cycle for selected non-isolated converters namely buck, boost and buck-boost converters. An example of inductor design procedure using the area-product method is shown for a buck converter operating in continuous conduction mode (CCM). The amplitude spectra of the inductor current, winding resistance and winding power loss are illustrated. Inductor winding losses in the designed inductor are analysed using MatLab simulations. Experimental results using the designed inductor are also presented.