Grounding systems modeling for high frequencies and transients: some fundamental considerations

In spite of large amount of research work in the last decades on the grounding systems modeling for high frequencies and transients there is no consensus on its practica applicability. This work points to some issues that may be important in the systematic approach to determine the validity domains of the different existing methods for analysis. In particular, the following topics are discussed: the evaluation of the upper frequency of interest in the transient study, the limitations due to the electrical dimensions of the system, and due to the underlying circuit concepts, especially in relation to the definition of impedance to ground. As a basis for the evaluation of the validity domains of more simplified quasi-static and circuit based models a full-wave electromagnetic model is described. Validation by comparison with experiment and illustrative numerical results are presented.