Identifying the Rating of the Unified Power Controller According to Unbalanced Distribution System Requirements

Unbalanced loading in distribution systems can cause serious issues such as high power losses and voltage instability. To address these issues, there is a high demand for devices that can balance unbalanced loading, so this paper presents a method for designing the ratings of a unified power flow controller (UPC), UPC is a device that can control and balance the active and reactive power flows through a three-phase transmission line by injecting current using variable coefficient transformer. The determination of the UPC rating depends on the load profile of the unbalanced distribution system, also the rating of the UPC depends on their use as active and reactive power balancer or as active power balancer and reactive power compensator. The procedure is applied to a standard 13-bus IEEE unbalanced distribution system with different load scenarios to evaluate UPC performance in each case. This provides a systematic approach for selecting appropriate UPC ratings to enhance power quality and reliability in an unbalanced distribution system.