Strengthening Power Quality in Active Distribution Network via Harmonics filters Integration

Abstract

Rapid urbanization and changing energy demands have made the delivery of clean and reliable electricity increasingly critical. Renewable systems have also become more popular in recent years owing to the increased demand for clean energy sources. Wind systems have the advantage of being able to utilize the abundant and free energy provided by the wind. However, the harmonics produced by the fluctuating incident energy from renewable sources could lead to subpar system performance. Both power producers and consumers now consider power quality to be a significant concern. The frequent use of power electronic devices and nonlinear loads in regular usage schedules introduces harmonic distortions into the electrical distribution network. Power quality is negatively impacted by harmonics in multiple ways, including decreased power-generating efficiency, voltage distortion, increased operating expenses, equipment overheating, transformer saturation, electromagnetic interference, etc. To address these issues, it is pivotal to use a well-suited filtration technique and to evaluate its performance in the context of harmonic reduction. The integration of filters is one of the foremost methods for harmonic mitigation. Since the mission is always to increase power quality while using the fewest possible filtering units, this study presents a harmonic mitigation framework for an IEEE 33-bus active distribution network (ADN) comprising a wind farm, a battery energy storage system (BESS), and an electric vehicle (EV) charging station. Harmonic propagation is assessed by evaluating the Total Harmonic Distortion (THD) across all buses in distribution network, enabling identification of the most vulnerable buses. Based on the harmonic assessment, Single-Tuned Filters (STFs) are strategically deployed at Buses 15, 29, and 33 to suppress the dominant fifth-order harmonic. Simulation results demonstrate a maximum THD reduction of 65.38% at Bus 33.The proposed STF allocation significantly mitigates harmonic distortion across the network; however, a limited number of buses continue to exhibit THD values exceeding the IEEE 519 recommended limit of 5%, indicating scope for further optimization or complementary harmonic mitigation measures. Overall, the proposed selective STF placement strategy effectively enhances power quality, offering a practical and economically viable solution for harmonic mitigation in renewable-integrated active distribution networks.