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

Unified Power Quality Conditioner (UPQC) is one of the most advanced Custom-Power-Devices in use today to improve the quality of Power (PQ) in the distribution network. UPQC compensates both voltage and current related PQ disturbances. Its control in unbalanced and distorted weak grid condition is of research interest. Also the performance of UPQC in the presence of unbalanced and non-linear harmonic loads is critical to maintain desirable PQ. In this work, a Self-Tuning Filter (STF) is implemented on the controller part to improve the performance of UPQC in the weak grid voltage along with current unbalance and distortion. The studied control structure gives an adequate voltage and current compensation for voltage sag with distorted voltage conditions, and also for unbalanced current conditions. A three-phase system is modelled in MATLAB/Simulink. The results of simulation study are presented to verify the effectiveness of the proposed control technique.