Improved method of power inductor design with DC current impact

The DC current impact on the ratio between AC and DC resistance of inductor winding (Fr) is examined for the practical applications. Relevant F
_r
equations are derived and applied to an optimization algorithm to determine the minimum winding loss at a given the ratio of DC current to AC current (k). It has been found that the curves of F
_r
versus the ratio of k exhibit a peak at a critical ratio. Below or above this critical ratio, the F
_r
decreases generally.