> Archives > To Be Published Recently Accepted Papers Precise Modeling and Adaptive Feed-Forward Decoupling of Unified Power Quality Conditioners Yingpin Wang†, Rubangakene Thomas Obwoya*, Zhibo Li*, Gongjie Li*, Yi Qu*, Zeyu Shi**, Feng Zhang** and Yunxiang Xie** Abstract The unified power quality conditioner (UPQC) is an effective custom power device that is used at the point of common coupling to protect loads from voltage and current-related PQ issues. Currently, most researchers have studied series unit and parallel unit models and an idealized transformer model. However, the interactions of the series and parallel converters in AC-link are difficult to analyze. This study utilizes an equivalent transformer model to accomplish an electric connection of series and parallel converters in the AC-link and to establishes a precise unified mathematical model of the UPQC. The strong coupling interactions of series and parallel units are analyzed, and they show a remarkable dependence on the excitation impedance of transformers. Afterward, a feed-forward decoupling method based on a unified model that contains the uncertainty components of the load impedance is applied. Thus, this study presents an adaptive method to estimate load impedance. Furthermore, simulation and experimental results verify the accuracy of the proposed modeling and decoupling algorithm. Keyword power quality, UPQC, precise unified modeling, interaction analysis, adaptive feed-forward decoupling PDF