Increasing Energy Storage Capabilities of Powder Cores by Adapting the Winding and the Use of Fringing Flux

Abstract:
Soft magnetic powder cores with a permeability of 14 to 160 are widely used in the design of storage chokes and coupled inductors. Their main advantage is the absence of a discrete air gap, which keeps the fringing minimized and equally distributed around the whole core. Placing the winding in a specific manner can help to design chokes with higher inductance and so higher energy storage capabilities. The theory of how to place the winding to get the desired effect is explained and measurements on practical examples are shown as well as the influence on parasitic effects.