Contribución al desarrollo tecnológico de la interconexión de plantas fotovoltaicas con redes de distribución

Abstract

This Doctoral Thesis gives an overview of the requirements that permit the interconnection of photovoltaic-distributed generation (PVDG) in their respective distribution networks. For this purpose, we have analysed lots of codes that have been proposed and enacted in many countries. As a conclusion, recommendations are given regarding the protection relays that should be used and their optimal settings. Also, this Thesis describes a hitherto unstudied malfunction that can occur in the protection system of distribution networks in the presence of photovoltaic plants. The focus here is on the phase-balance current protection of overhead or blended feeders back-fed by PVDGs. Low power quality or ferroresonant states were found to be the causes of the malfunction of that protection, which led to its untimely tripping. The results of this study highlight the need to modify current protection practices and to elaborate new power quality requirements for PVDG.