Impedance Modeling of Low-Voltage Cables Considering Capacitances and Parameter Uncertainty Using Finite-Element Method

Recent research presented methods to improve the calculation of low voltage cable parameters by using finite-element models due to increasing focus on power quality issues in distribution grids. However, the focus was mostly on series parameters and nominal frequency. In this paper the calculation of cable capacitances as well as their impact on harmonic impedance of a single cable and in a rural low voltage grid is discussed using detailed finite-element models. Moreover, the accuracy of geometric simplification was quantified. The results are used to compare and optimize existing analytical equations. Furthermore, sources of uncertainty in cable modeling were identified and their range of impact on impedance was subsequently studied to give recommendations regarding necessary study cases for a robust assessment of grid impedance.