Alternating Current Conductor Losses

This chapter considers alternating current (AC) conductor losses and skin effect in the context of both strip conductors and then round conductors, and focuses on proximity effect. Skin effect is a phenomenon in which current density becomes concentrated at the outside of a conductor rather than being uniformly distributed. Skin effect is associated with AC currents and becomes increasingly pronounced as frequency increases. Proximity effect is a loss mechanism in which a time-varying field from nearby conductors induces eddy currents in a given conductor. The chapter aims to demonstrate why the two loss mechanisms may be treated separately. It also considers the calculation of the proximity-effect loss for an entire winding, and these losses for particular cases, including rotating machinery and a UI-core inductor. The chapter concludes by considering the ac conductor losses in rotating electric machinery and in a UI-core inductor.