Three-Phase-Measurement-Based Load Modeling Technique Using Unbalanced Fault Data

Abstract

This study presents a load modeling technique using unsymmetrical fault data. Typically, three-phase balanced fault data are prerequisite for load modeling; however, the existing technique utilizes only positive sequence data. Obtaining symmetrical data from a real power system is very difficult as three-phase faults are very rare. In this study, I aimed to improve existing methods designed for estimating load parameters from three-phase symmetrical fault data via load modeling of unsymmetrical faults. The proposed method corrects the existing algorithm using positive sequence data along with three-phase data, namely phases-A, -B, and -C. The equation for each phase of the load model is obtained and subsequently used for load parameter estimation. The load model parameters are estimated using the data obtained from phases-A, -B, and -C, unlike in existing load models that use only positive sequence data. Unsymmetrical faults occur more frequently in a system than symmetrical faults, and numerous opportunities for load model parameter estimation are available. Applying this algorithm to the three-phase data collected using phasor measurement unit-like data acquisition devices is expected to considerably increase both the parameter estimation accuracy and frequency during load modeling parameter estimation in the future.