Reduced Complexity Estimation of Neutral Voltages in Terms of Grounding Impedances via Phasor Interpolation

A novel method based on phasor interpolation is proposed for solving the distribution system problem of computing bus neutral voltages as functions of bus grounding impedances. The proposed approach has the salient feature of exponentially reduced computational complexity, with respect to the number of groundable buses, when compared to the standard procedure of iterating load flow for all grounding impedance setups. This is achieved by computing load flow for a subset of grounding impedances and subsequently estimating voltage for the remaining cases via phasor interpolation. To validate the proposed method, case studies based on computer simulations are considered for assessing estimation error and processing time of the proposed method. Obtained results confirm that the proposed methods yields significant reduction of execution time with low error in the estimation of neutral voltages, compared to exact results computed via standard procedures based on iteration of load flow algorithms.