The unified power quality conditioner: the integration of series- and shunt-active filters

TLDR

Unified power quality conditioners integrate series‑ and shunt‑active filters to improve voltage stability, reactive power, and harmonic distortion in distribution and industrial systems. The study aims to compensate voltage flicker, imbalance, reactive power, negative‑sequence current, and harmonics using a UPQC. The authors present a control strategy that regulates instantaneous active and reactive powers within the UPQC. Laboratory experiments on a 20 kVA model and theoretical analysis confirm the UPQC’s viability and effectiveness.

Abstract

This paper deals with unified power quality conditioners (UPQCs), which aim at the integration of series-active and shunt-active power filters. The main purpose of a UPQC is to compensate for voltage flicker/imbalance, reactive power, negative-sequence current and harmonics. In other words, the UPQC has the capability of improving power quality at the point of installation on power distribution systems or industrial power systems. This paper discusses the control strategy of the UPQC, with a focus on the how of instantaneous active and reactive powers inside the UPQC. Experimental results obtained from a laboratory model of 20 kVA, along with a theoretical analysis, are shown to verify the viability and effectiveness of the UPQC.