Extra losses caused in high current conductors by skin and proximity effects

A century ago, Lord Kelvin showed that any rapid change of current intensity in a conductor modifies the current density in the various pans of this conductor. The author recalls the consequences of the skin and proximity effects in the case of electrical conductors designed for high currents. More attention should be paid to these phenomena in the case of the designing of certain busbars since it is clear that this particularity, often neglected, leads to an overdimensioning of the conductors, higher energy losses and poor overall operational efficiency.