Dual Unified Power Quality Conditioner Based on Open-Winding Transformers and Series Converters for Grid-Connected PV Systems

A new scheme for a grid connected photovoltaic system capable of enhancing power quality of a distribution system is presented in this paper. The proposed system is consisted of a dual unified power quality conditioner (D-UPQC) based on open-end winding (OEW) transformer and series connected converters. The D-UPQC is consisted of four series converters connected to the grid via two three-phase transformer with open-end winding on the converters side. The proposed scheme uses two PV arrays, each array feeds a separate dc-link of a two three phase voltage source converter (VSC). The structure, control and capability of the proposed configuration are discussed in this paper. The effectiveness of the proposed configuration has been verified through simulation studies using Simulink/Matlab.