PLC-BASED MONITORING AND CONTROL OF DISTRIBUTED GENERATION AND STORAGE SYSTEMS IN LV SMART GRIDS: ARCHITECTURE, DEVICES AND CHANNEL CHARACTERIZATION TOOLS

The fast deployment of renewable generation technologies has deeply altered the structure of the electricity grid, at all voltage levels, from transmission networks to residential dwellings. In this framework, an accurate monitoring of bidirectional power flows is an essential requirement for smart grid stability [1]-[4]. Besides powers, also other quantities such as drained, injected and stored energy, current, voltage, frequency, and also power quality indexes have to be monitored. This can be obtained only by integrating modern technologies for accurate monitoring, with remote control of distributed generation (DG) and energy storage systems (ESSs), and with the support of a reliable communication infrastructure between prosumers and the Distribution System Operator (DSO). This is the well know implementation of smart grids (SGs) paradigm [5]-[6]. The capacity to establish a communication channel between the management systems of the new facilities (i.e. distributed generators and energy storage systems) and the DSO is a crucial component of this new kind of infrastructure. Several research studies on the use of different communication technologies in SGs have been presented in recent years. The authors specifically investigated the usage of power line communication (PLC) technology both on low voltage (LV) and medium voltage (MV) networks [7]-[9]. In fact, PLC is a prominent communication technology in distribution networks, because it has the key benefits of inexpensive installation cost and resilience, as it uses the power grid as the communication link. PLC is used on LV grids across the world for automatic meter reading and it has recently been proposed for other use cases such as secondary substation automation, remote control of distributed generators, and other smart grid solutions [6]. In this paper, a new architecture is proposed for smart grid deployment, which is based on the use of PLCs. The proposed architecture includes the use of two devices: a concentrator, installed in a secondary substation, and a PLC communication bridge, to be connected to the generation/storage system. Differently from previous studies of the authors, where a dedicated interface protection system (IPS) was developed according to CEI 0-21 standard [6], the communication bridge herein proposed can be connected to commercial IPS, even those already installed. Thus the proposed solution is more flexible and it could be deployed in any country, with IPS compliant to the related.