Accurate Numerical Modelling of MV and HV Resistive Dividers

An effective computational tool for the simulation and design of voltage dividers has been realized. It takes advantage from a finite element procedure for the accurate computation of the divider stray capacitances. These latter are then the input of a circuit solver procedure based on the modified node potential technique, which provides the divider frequency response. Furthermore, a test divider has been setup for the purpose of the tool validation. A very good agreement has been found between measured and computed results. This paper highlights that a correct representation of the resistors is necessary in the FEM model, during the computation of the stray parameters. This issue has been clarified for the first time in this paper. In addition, a comparison between FEM and BEM methods has been carried out before the implementation of the numerical code, stating the superior effectiveness of FEM. The computational tool has been finally tested on a real voltage divider. Good results have been found in terms of computational accuracy. Limited discrepancies between measured and computed results have been found up to 10 kHz, being 5.7 % for the scale factor and less than 24 mrad for the phase errors.