Optimal choice for number of strands in a litz-wire transformerwinding

摘要

The number and diameter of strands to minimize loss in a litz-wirentransformer winding is determined. With fine stranding, the ACnresistance factor can be decreased, but DC resistance increases as anresult of the space occupied by insulation. A power law to modelninsulation thickness is combined with standard analysis ofnproximity-effect losses to find the optimal stranding. Suboptimalnchoices under other constraints are also determined