Propagation of Current and Voltage Unbalance in Electrical Power Networks

This paper investigates the propagation of current and voltage unbalance in an electrical power network. Such a study will reveal the techniques for inhibiting unbalance propagation. Modeling of salient network components for unbalance propagation is presented. Improved models for quantifying current and voltage unbalance are developed. Models for assessing unbalance attenuation and propagation in a network are presented. The effects of transformer winding types on unbalance propagation is presented. Case studies were used to establish unbalance propagation pattern. It was found that transformer and its winding type has the greatest effect on the attenuation and propagation of unbalance in a network. Transformer with wye neutral/wye neutral winding type is found to be the best in attenuating the unbalance caused by an electrical load. The theoretical findings were validated by capturing and analyzing real-time data on networks that supply electrical power to steel producing plants.