Power quality improvement by a 3-phase 4-leg supercapacitor based DSTATCOM

Power Quality Issues are the main challenging issues in a distributed power system due to the integration of renewable energy sources into the grid and huge utilization of semiconductor-based devices. In this paper, a supercapacitor based distributed static compensator (DSTATCOM)is presented to mitigate the power quality problems. The compensator (Supercapacitor based DSTATCOM) mainly focused on harmonics mitigation, unbalanced current reduction, power factor correction and reactive power compensation of the power system. The dc-link voltage of the DSTATCOM is regulated by the supercapacitor throughout the compensation process very quickly. Electrical energy from the grid is stored by the supercapacitor during off-peak hours and delivered back to the grid during peak hours for system stability, reliability and power quality improvement. The instantaneous symmetric component theory (ISCT) control strategy is used to generate the gate signals for IGBTs of the voltage source converter (VSC) based DSTATCOM. Also, total harmonic distortion (THD) of the supply current is maintained well below the IEEE standards on the harmonic limit. The proposed system has been simulated in the SimPowerSystem (SPS)/Matlab-Simulink environment to verify its effectiveness over conventional DSTATCOM.