A New Solution for Low-Voltage Distributed Generation Interface Protection System

Abstract

In this paper, a new solution is proposed for the remote monitoring and control of distributed generators (DGs) and energy storage systems (ESSs) connected to low-voltage distribution networks. The proposed system fulfills the in-force standard requirements for the connection of DGs to the utility grid. Moreover, it allows implementing some enhanced functions for the remote control of inverters of DGs and ESSs, not only in terms of disconnection but also in terms of voltage regulation and power shuttering. The proposed solution is based on a new interface protection system and a dedicated secondary substation concentrator, which allows the communication between the distributed system operator and the inverters of DGs or ESSs. The proposed system was tested on field in the electrical network of the island of Ustica. An experimental characterization was carried out to find the best communication conditions, i.e., the frequency band with the lowest noise and attenuation, considering the signal amplitude and signal-to-noise ratio constraints, as well as the desired transmission data rate and transfer time.