Harmonic Mitigation in Nonlinear Load Systems Using D-STATCOM

Nonlinear loads such as adjustable speed drives, rectifiers, and power electronic converters inject significant harmonic currents into the power system, degrading power quality and causing excessive Total Harmonic Distortion (THD). This paper presents a simulation-based performance analysis of a Distribution Static Compensator (D-STATCOM) for harmonic mitigation under nonlinear load conditions. A MATLAB/Simulink model is developed to evaluate the system with and without the D-STATCOM. Without compensation, the voltage and current THD is observed to be approximately 27.21%, which is far above the limit recommended by IEEE Std. 519. With the D-STATCOM connected, the THD is reduced to approximately 7.58%, and the source current waveform becomes near-sinusoidal. The results demonstrate that the proposed D-STATCOM effectively mitigates harmonics and improves power quality, and directions for further improvement toward full standard compliance are discussed.