Power Quality Enhancement of a Radial Distribution Network Using PV Systems, SVCs, and Single-Tuned Passive Filters: A Case Study of the KO5 Feeder of Mekelle’s electrical distribution network in northern Ethiopia

Abstract

This study investigates the power quality in the KO5 feeder in Mekelle's electrical distribution network in northern Ethiopia; the KO5 feeder has a bad voltage profile, excessive power loss, significant harmonic distortion, and a low power factor. A primary goal of this research was to improve the KO5 feeder's system performance by combining photovoltaic (PV) arrays, Static VAR Compensators (SVCs), and single-tuned passive filters (STPFs) as part of a hybrid solution. A model for the system was developed and run with simulations using ETAP 19.0 in both full-load (FL) and 70% partial-load (70% FL) operating condition. The optimal size and location of PV arrays at buses 106 and 109 was identified through simulation analysis, while eight SVC units were installed at the weakest buses in the network in order to improve voltage level and the flow of reactive power. The harmonic analysis indicated that the 5^th and 7^th harmonic contributed most of the distortion, therefore, STPFs were designed and implemented to the buses with the highest amounts of distortion. The proposed configuration resulted in a large drop in the total amount of power losses within the system from 1.474 MW to 0.270 MW at FL and from 0.647 MW to 0.096 MW at 70% FL. Furthermore, the minimum bus voltage increased from 78.1% per unit (pu) to 91.9% pu at full load, and from 85.6% pu to 95.6% pu at 70% full load, as well as an increase in the total system power factor. Therefore, these results indicate an improvement in reactive power management for the distribution system. In addition, the total harmonic distortion (THD) has been minimized below 5%; so that it complies with the IEEE 519-2022 standards, thus, the results indicate that the combined insulation of PV arrays, SCVs and passive filters is an economical method to enhance voltage stability, reduce energy loss, improve power factor, and improve overall power quality on radial distribution systems.