Design of Unified Power Quality Conditioner for Power Quality Improvement in Distribution Network

Abstract

Unified Power Quality Conditioner (UPQC) is one ofthe most advanced Custom-Power-Devices in use today to improvethe quality of Power (PQ) in the distribution network. UPQCcompensates both voltage and current related PQ disturbances. Itscontrol in unbalanced and distorted weak grid condition is ofresearch interest. Also the performance of UPQC in the presenceof unbalanced and non-linear harmonic loads is critical tomaintain desirable PQ. In this work, a Self-Tuning Filter (STF) isimplemented on the controller part to improve the performance ofUPQC in the weak grid voltage along with current unbalance anddistortion. The studied control structure gives an adequate voltageand current compensation for voltage sag with distorted voltageconditions, and also for unbalanced current conditions. A threephasesystem is modelled in MATLAB/Simulink. The results ofsimulation study are presented to verify the effectiveness of theproposed control technique.