A simplified and accurate calculation of frequency dependence conductor impedance

This paper illustrates a simple and direct approach for the calculation of the impedance of transmission line as a function of frequency. The approach considers the analysis of skin effect in some multistrand conductors. Two essential types of conductors, stranded wires and aluminum conductor steel reinforced (ACSR), are treated. Simple approximations are proposed, to substitute the long and complicated operation of Bessel functions analysis. One of the equations can be used for low frequencies and the other for high frequencies. To determine the frequency at which each of these equations can be applied, the geometric mean radius (GMR) of the wire is linked to the frequency by a defined formula The validity of these equations has been tested at Hydro-Quebec Research Institute. The validation and the experimental results are included. The resolution of the current distribution equations in a conductor by Bessel functions is also provided