Authors: Hachimenum Nyebuchi Amadi, Happy Prince Nwokoegi, Richeal Chinaeche Ijeoma
Abstract: Distribution efficiency in developing power systems is often undermined by excessive reactive power demand, poor voltage regulation, and high technical losses. The Port Harcourt mainstream 33 kV distribution network in Nigeria, a critical urban supply corridor, is particularly vulnerable to these inefficiencies due to its radial structure, overloaded transformers, and weak reactive power support. Such conditions result in low power factor, under voltage problems, and distribution losses that exceed international performance standards, thereby threatening supply reliability and quality of service. In this study, the Port Harcourt 33 kV distribution network was modeled in MATLAB/Simulink to evaluate its operational performance and investigate the effectiveness of advanced power factor correction (PFC) using a Distribution Static Synchronous Compensator (D-STATCOM). Baseline simulations revealed progressive voltage deterioration along the feeder, with the weakest bus falling to 0.910 p.u., well below the operational limit of 0.95 p.u. Furthermore, the system recorded active power losses of 1.604 MW, equivalent to 9.5% of peak demand, substantially higher than the 2–6% technical loss benchmark recommended by IEEE for efficient distribution systems. Following the integration of D-STATCOM into the network, remarkable improvements were observed. All bus voltages were restored within 0.989-0.999 p.u., with the weakest bus improved from 0.910 p.u. to 0.989 p.u., thereby ensuring compliance with the 0.95-1.05 p.u. standard. In addition, total technical losses decreased sharply to 0.283 MW, equivalent to 2.0% of peak demand, placing the network well within international best-practice thresholds. The findings confirm D-STATCOM as an effective and sustainable solution for improving voltage stability, minimizing technical losses, and enhancing reliability in urban distribution networks.