Design and simulation of a power quality improvement system for medium/low-voltage distribution networks

Abstract

Power quality disturbances such as harmonic distortion, voltage fluctuations, and poor power factor pose significant challenges to industrial processes, especially in rural and semi-urban areas of Uganda where power infrastructure is limited. The Kigezi Highland Tea Factory, a key agro-industrial facility, experiences frequent operational inefficiencies and equipment failures due to these power quality issues. This project presents the design and simulation of a Universal Active Power Filter (UAPF) aimed at improving the power quality of the factory’s low-voltage distribution network. The proposed system was modeled using MATLAB/Simulink and incorporated a Proportional-Integral (PI) controller for regulating the DC-link voltage and a Hysteresis Current Controller (HCC) for realtime Harmonic current compensation. A nonlinear load, representative of the factory’s actual operational conditions, was simulated to assess the system’s performance. Simulation Results demonstrated a significant reduction in Total Harmonic Distortion (THD) From 19.18% to 4.9%, improved power factor from, and effective balancing of phase currents.

The findings confirm that the UAPF, when equipped with appropriate control strategies, can effectively mitigate power quality problems in industrial low-voltage networks. The system offers a scalable and adaptable solution for similar industrial facilities across Uganda, contributing to more reliable and efficient energy use.