ANALYSIS OF POWER QUALITY DISTURBANCE DUE TO VOLTAGE SAG ON 33/11 KV NETWORK WITH DIFFERENT TRANSFORMER CONFIGURATION

This paper investigates the impact of voltage sags on power quality in a 33/11 kV distribution network by analyzing the behavior of different transformer configurations under various fault conditions. Voltage sag, a critical power quality disturbance, affects industrial performance and equipment reliability. Using MATLAB/Simulink, the 33/11 kV network supplying Shakti Nagar (MPPTCL) was modeled and subjected to different types of faults (SLG, DLG, DL, and 3-Φ). Simulation results were analyzed across three transformer configurations—Yg-Yg, Yg-Δ11, and Yg-Y. The performance of each configuration was compared using RMS voltage drop and voltage sag indices. The study concludes that transformer connection significantly influences the severity of voltage sag. The Yg-Y configuration offered the most stable response under SLG fault, while Yg-Δ11 performed better under DL and DLG faults.