A Model for an Interconnected Photovoltaic System using an Off-grid Inverter as a Reference Node

Abstract

This paper presents the results of a research work where an intentional connection is made in island mode, a low power isolated photovoltaic system (300W) is used as a reference for an interconnected photovoltaic system (1,270W). The objective is to look at its viability in situations where the electricity grid constantly fails. The electrical models of both systems (converter, inverter and LCL filter) are used, with the help of an intelligent controller using the technique of artificial neural networks, for the activation and deactivation of ballast loads to maintain the voltage level at 120 VRMS and balance the active power produced by the interconnected system and the active power consumed by the load. When performing the simulation, we are focus on the functionality of the proposed system, evaluating response times of the intelligent controller, % THD and RMS level of the voltage in the load according to the IEEE-Std-1159-1995 standard. The tests are made in scenarios of stability and variation in solar radiation, the power produced by the interconnected system and the power consumed by the load.