Mitigation of Power Quality Problems Using Unified Power Quality Conditioner by an Improved Disturbance Extraction Technique

Voltage sag is the most severe power quality (PQ) problem while current harmonics are the most common PQ problem. In this paper, a unified power quality conditioner (UPQC) mechanism is presented that mitigates these power quality problems. This UPQC is the custom power device for mitigating the PQ problems. It combines both a series part that mitigates voltage related PQ problems and a shunt part that mitigates current related PQ problems. An improved extraction technique is introduced to extract voltage and current disturbances to help operate the UPQC that mitigates these disturbances simultaneously to enhance the PQ in the distribution system. Simulation results using MATLAB/Simulink are provided to illustrate the meritorious performance of the presented extraction technique.