Skin Effect in Multiple and Polyphase Conductors

The modal theory of current flow, previously successful in predicting skin-effect behavior of single isolated conductors, is generalized to apply to any number of parallel conductors arbitrarily arranged in space and excited electrically by arbitrary currents. The distribution of current density within each conductor is found in terms of a summation of the modal functions, and the terminal parameters of the system of conductors are given as an impedance matrix relating the total conductor currents to the voltage drops in the various conductors. Sequence impedances, losses, and other electrical properties are then calculable from the basic impedance matrix.