High-frequency ac losses are normally induced in transformer and induc
tor windings due to skin, proximity, fringing, and other ac effects. I
n addition, the winding structure greatly affects the distribution of
losses within the windings. Air gaps are usually placed in the core of
magnetic devices to support the high magnetic motive force (mmf), Fri
nging fields can cause additional ac winding losses, and care must be
taken to minimize the additional losses. In this paper, the effect of
air-gap design on the induced losses will be investigated. In particul
ar, three air-gap designs-lumped, discretely distributed, and uniforml
y distributed-will be investigated and evaluated. Both one-dimensional
(1-D) and finite-element analyses (FEA's) are used to investigate the
different design structures.