Assessment and Mitigation of Power Quality Issues in Presence of Optimally Placed DGs in Radial Distribution System Using Heuristic Optimization Algorithms

Abstract

Distributed Generation (DG) integration plays a significant role in improving the efficiency, reliability, and power quality of modern radial distribution systems. However, improper DG placement and sizing can lead to high power losses, unstable voltage profiles, and poor power quality act under changing load conditions. This study aims to improve power quality in the IEEE 33-bus radial distribution system by minimizing real power loss, Total Harmonic Distortion (THD), and voltage sag through optimal DG placement and sizing. A 24-hour load variation profile is considered to represent realistic operating conditions. The Backward-Forward Sweep (BFS) load flow method is utilized to calculate bus voltages, line currents, and power losses, while the Artificial Bee Colony (ABC) algorithm is useful to solve the multi-objective optimization problem involving power loss, THD, voltage deviation, and voltage sag index. Simulation results prove significant improvements after DG integration. The total active power loss is reduced from 159.1074 kW to 54.173 kW, achieving a 65.95% reduction, while the minimum bus voltage expands from 0.9188 p.u. to 0.9678 p.u. The total THD is reduced from 5.2716% to 2.6168%, while the voltage sag index decreases from 0.1958 to 0.1192. The results confirm the use of the proposed ABC-BFS approach for improving overall system performance and power quality under realistic operating conditions.