THD analysis with custom power devices at distorted load conditions: Implementation of UPQC using PI-Resonant controller

摘要

Abstract—Power Quality (PQ) mainly deals with issues like maintaining a fixed voltage at the Point of Common Coupling (PCC) for various distribution voltage levels irrespective of voltage fluctuations, maintaining near unity power factor power drawn from the supply. Flexible AC Transmission Systems (FACTS) and Custom Power products like STATCOM, DVR and UPQC deal with the issues related to power quality using similar control strategies and concepts. Unlike DVR and STATCOM, unified power quality conditioner (UPQC) employs the integration of both series-active and shunt-active power filters to mitigate any type of voltage and current fluctuations and power factor correction in a power distribution network. The unified power quality conditioner (UPQC) is being used as a universal active power conditioning device to mitigate both current and voltage harmonics at a distribution side of power system network. This paper emphasizes the importance of UPQC application for better power quality, by comparing the mitigated voltage and current THD values among DSTATCOM, DVR & UPQC connected to a system with a distorted load. There after a novel design of UPQC is implemented using PI-Resonant control strategy for further mitigating THD’S of voltage and current at the load side in the system.