Distributed generation integrating a photovoltaic-based system with a single- to three-phase UPQC applied to rural or remote areas supplied by single-phase electrical power

Abstract

This paper presents a distributed generation (DG) system integrating a photovoltaic (PV) system with a 1-Phase to 3-Phase unified power quality conditioner (UPQC-1PH-3PH). The system named DG-UPQC-1PH-3PH injects into the grid the energy produced from a PV array, contributing to feed loads connected to a local three-phase four-wire electrical system, to attend consumers of rural and/or remote areas supplied by single-phase utility. Besides the injection of active power into the grid, the DG-UPQC-1PH-3PH improves power quality indicators, such as voltage sags/swells, grid voltage harmonics, and power factor. Multi-resonant state-feedback controllers are employed to ensure sinusoidal grid current and load voltages, while an effective PV array voltage control is achieved by using a multi-loop proportional-integral controller. Since the DG-UPQC-1PH-3PH inverters handle the power produced by the PV system plus those demanded by the load, the converters sizing must be carefully performed. Thus, curves that allow the sizing of the power converters based on the power flow through the converters are presented. The static performance is experimentally tested considering several operation conditions involving the utility grid voltage, load and energy produced by the PV array, while its dynamic behavior is evaluated when the PV array is subjected to abrupt solar irradiation changes.