Application of Finite-Element Method to Calculation of the Impedance of Nonsymmetrically Shaped Bars Conducting Current

Since good basic design for electromagnetic compatibility often entails knowledge (sometimes unavailable) of the effective resistance and reactance of conductors, information on this subject is presented here. In this paper, the finite-element method is applied to calculation of the impedance of alternating-current-carrying conductors with open (all external) boundaries. With use of the finite-element version based directly on the Bubnov- Galerkin method for conducting regions of polygonally shaped bars, and the separation-of-variables method for external regions, relationships that can be numerically interpreted are obtained. On the basis of the calculations performed, the plots of relative resistances and internal reactances are presented as a function of conductor width to skin depth for several practical cases of nonsymmetrically shaped bars conducting sinusoidal current.